chrome/browser/chrome_browser_main.cc

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/chrome_browser_main.h"

#if defined(TOOLKIT_GTK)
#include <gtk/gtk.h>
#endif

#include <string>
#include <vector>

#include "base/at_exit.h"
#include "base/bind.h"
#include "base/command_line.h"
#include "base/cpu.h"
#include "base/debug/trace_event.h"
#include "base/file_util.h"
#include "base/files/file_path.h"
#include "base/metrics/field_trial.h"
#include "base/metrics/histogram.h"
#include "base/path_service.h"
#include "base/prefs/json_pref_store.h"
#include "base/prefs/pref_registry_simple.h"
#include "base/prefs/pref_service.h"
#include "base/prefs/pref_value_store.h"
#include "base/process_info.h"
#include "base/process_util.h"
#include "base/run_loop.h"
#include "base/string_piece.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_split.h"
#include "base/sys_info.h"
#include "base/sys_string_conversions.h"
#include "base/threading/platform_thread.h"
#include "base/threading/sequenced_worker_pool.h"
#include "base/time.h"
#include "base/utf_string_conversions.h"
#include "base/values.h"
#include "build/build_config.h"
#include "chrome/browser/about_flags.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/browser_process_impl.h"
#include "chrome/browser/browser_shutdown.h"
#include "chrome/browser/chrome_browser_main_extra_parts.h"
#include "chrome/browser/component_updater/component_updater_service.h"
#include "chrome/browser/component_updater/flash_component_installer.h"
#include "chrome/browser/component_updater/pnacl/pnacl_component_installer.h"
#include "chrome/browser/component_updater/recovery_component_installer.h"
#include "chrome/browser/component_updater/swiftshader_component_installer.h"
#include "chrome/browser/defaults.h"
#include "chrome/browser/extensions/extension_protocols.h"
#include "chrome/browser/extensions/extension_service.h"
#include "chrome/browser/extensions/startup_helper.h"
#include "chrome/browser/first_run/first_run.h"
#include "chrome/browser/first_run/upgrade_util.h"
#include "chrome/browser/google/google_search_counter.h"
#include "chrome/browser/google/google_util.h"
#include "chrome/browser/gpu/chrome_gpu_util.h"
#include "chrome/browser/gpu/gl_string_manager.h"
#include "chrome/browser/jankometer.h"
#include "chrome/browser/managed_mode/managed_mode.h"
#include "chrome/browser/metrics/field_trial_synchronizer.h"
#include "chrome/browser/metrics/metrics_log.h"
#include "chrome/browser/metrics/metrics_service.h"
#include "chrome/browser/metrics/thread_watcher.h"
#include "chrome/browser/metrics/tracking_synchronizer.h"
#include "chrome/browser/metrics/variations/variations_service.h"
#include "chrome/browser/nacl_host/nacl_process_host.h"
#include "chrome/browser/net/chrome_net_log.h"
#include "chrome/browser/net/crl_set_fetcher.h"
#include "chrome/browser/notifications/desktop_notification_service.h"
#include "chrome/browser/notifications/desktop_notification_service_factory.h"
#include "chrome/browser/page_cycler/page_cycler.h"
#include "chrome/browser/performance_monitor/performance_monitor.h"
#include "chrome/browser/performance_monitor/startup_timer.h"
#include "chrome/browser/plugins/plugin_prefs.h"
#include "chrome/browser/policy/policy_service.h"
#include "chrome/browser/prefs/chrome_pref_service_factory.h"
#include "chrome/browser/prefs/command_line_pref_store.h"
#include "chrome/browser/prefs/scoped_user_pref_update.h"
#include "chrome/browser/printing/cloud_print/cloud_print_proxy_service.h"
#include "chrome/browser/printing/cloud_print/cloud_print_proxy_service_factory.h"
#include "chrome/browser/process_singleton.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/profiles/profile_manager.h"
#include "chrome/browser/search_engines/search_engine_type.h"
#include "chrome/browser/search_engines/template_url.h"
#include "chrome/browser/search_engines/template_url_prepopulate_data.h"
#include "chrome/browser/search_engines/template_url_service.h"
#include "chrome/browser/search_engines/template_url_service_factory.h"
#include "chrome/browser/service/service_process_control.h"
#include "chrome/browser/shell_integration.h"
#include "chrome/browser/three_d_api_observer.h"
#include "chrome/browser/translate/translate_manager.h"
#include "chrome/browser/ui/app_list/app_list_service.h"
#include "chrome/browser/ui/browser.h"
#include "chrome/browser/ui/browser_finder.h"
#include "chrome/browser/ui/host_desktop.h"
#include "chrome/browser/ui/startup/default_browser_prompt.h"
#include "chrome/browser/ui/startup/startup_browser_creator.h"
#include "chrome/browser/ui/uma_browsing_activity_observer.h"
#include "chrome/browser/ui/user_data_dir_dialog.h"
#include "chrome/browser/ui/webui/chrome_web_ui_controller_factory.h"
#include "chrome/common/child_process_logging.h"
#include "chrome/common/chrome_constants.h"
#include "chrome/common/chrome_paths.h"
#include "chrome/common/chrome_result_codes.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/env_vars.h"
#include "chrome/common/logging_chrome.h"
#include "chrome/common/metrics/variations/variations_util.h"
#include "chrome/common/net/net_resource_provider.h"
#include "chrome/common/pref_names.h"
#include "chrome/common/profiling.h"
#include "chrome/common/startup_metric_utils.h"
#include "chrome/installer/util/google_update_settings.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/notification_observer.h"
#include "content/public/browser/notification_registrar.h"
#include "content/public/browser/notification_service.h"
#include "content/public/browser/notification_types.h"
#include "content/public/common/content_client.h"
#include "content/public/common/content_switches.h"
#include "content/public/common/main_function_params.h"
#include "grit/app_locale_settings.h"
#include "grit/browser_resources.h"
#include "grit/chromium_strings.h"
#include "grit/generated_resources.h"
#include "grit/platform_locale_settings.h"
#include "net/base/net_module.h"
#include "net/base/sdch_manager.h"
#include "net/cookies/cookie_monster.h"
#include "net/http/http_network_layer.h"
#include "net/http/http_stream_factory.h"
#include "net/url_request/url_request.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/base/layout.h"
#include "ui/base/resource/resource_bundle.h"
#include "ui/base/resource/resource_handle.h"
#include "ui/base/touch/touch_device.h"
#include "ui/base/ui_base_switches.h"

#if defined(OS_ANDROID)
#include "base/android/build_info.h"
#endif

#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
#include "chrome/browser/first_run/upgrade_util_linux.h"
#endif

#if defined(OS_CHROMEOS)
#include "chrome/browser/chromeos/cros/cros_library.h"
#include "chrome/browser/chromeos/settings/cros_settings.h"
#include "chrome/browser/chromeos/settings/cros_settings_names.h"
#endif

// TODO(port): several win-only methods have been pulled out of this, but
// BrowserMain() as a whole needs to be broken apart so that it's usable by
// other platforms. For now, it's just a stub. This is a serious work in
// progress and should not be taken as an indication of a real refactoring.

#if defined(OS_WIN)
#include "base/environment.h"  // For PreRead experiment.
#include "base/win/windows_version.h"
#include "chrome/browser/browser_util_win.h"
#include "chrome/browser/chrome_browser_main_win.h"
#include "chrome/browser/first_run/try_chrome_dialog_view.h"
#include "chrome/browser/first_run/upgrade_util_win.h"
#include "chrome/browser/net/url_fixer_upper.h"
#include "chrome/browser/ui/network_profile_bubble.h"
#include "chrome/installer/util/helper.h"
#include "chrome/installer/util/install_util.h"
#include "chrome/installer/util/shell_util.h"
#include "net/base/net_util.h"
#include "printing/printed_document.h"
#include "ui/base/l10n/l10n_util_win.h"
#include "ui/base/win/dpi.h"
#endif  // defined(OS_WIN)

#if defined(OS_MACOSX)
#include <Security/Security.h>

#include "base/mac/scoped_nsautorelease_pool.h"
#include "chrome/browser/mac/keystone_glue.h"
#endif

#if defined(ENABLE_CONFIGURATION_POLICY)
#include "policy/policy_constants.h"
#endif

#if defined(ENABLE_GOOGLE_NOW)
#include "chrome/browser/ui/google_now/google_now_service_factory.h"
#endif

#if defined(ENABLE_LANGUAGE_DETECTION)
#include "chrome/browser/language_usage_metrics.h"
#endif

#if defined(ENABLE_RLZ)
#include "chrome/browser/rlz/rlz.h"
#endif

#if defined(TOOLKIT_VIEWS)
#include "ui/views/focus/accelerator_handler.h"
#endif

#if defined(USE_X11)
#include "chrome/browser/chrome_browser_main_x11.h"
#endif

using content::BrowserThread;

namespace {

enum UMATouchEventsState {
  UMA_TOUCH_EVENTS_ENABLED,
  UMA_TOUCH_EVENTS_AUTO_ENABLED,
  UMA_TOUCH_EVENTS_AUTO_DISABLED,
  UMA_TOUCH_EVENTS_DISABLED,
  // NOTE: Add states only immediately above this line. Make sure to
  // update the enum list in tools/histogram/histograms.xml accordingly.
  UMA_TOUCH_EVENTS_STATE_COUNT
};

void LogIntelMicroArchitecture() {
  base::CPU cpu;
  base::CPU::IntelMicroArchitecture arch = cpu.GetIntelMicroArchitecture();
  UMA_HISTOGRAM_ENUMERATION("Platform.IntelMaxMicroArchitecture", arch,
      base::CPU::MAX_INTEL_MICRO_ARCHITECTURE);
}

// This function provides some ways to test crash and assertion handling
// behavior of the program.
void HandleTestParameters(const CommandLine& command_line) {
  // This parameter causes an assertion.
  if (command_line.HasSwitch(switches::kBrowserAssertTest)) {
    DCHECK(false);
  }

  // This parameter causes a null pointer crash (crash reporter trigger).
  if (command_line.HasSwitch(switches::kBrowserCrashTest)) {
    int* bad_pointer = NULL;
    *bad_pointer = 0;
  }
}

void AddFirstRunNewTabs(StartupBrowserCreator* browser_creator,
                        const std::vector<GURL>& new_tabs) {
  for (std::vector<GURL>::const_iterator it = new_tabs.begin();
       it != new_tabs.end(); ++it) {
    if (it->is_valid())
      browser_creator->AddFirstRunTab(*it);
  }
}

// Returns the new local state object, guaranteed non-NULL.
// |local_state_task_runner| must be a shutdown-blocking task runner.
PrefService* InitializeLocalState(
    base::SequencedTaskRunner* local_state_task_runner,
    const CommandLine& parsed_command_line,
    bool is_first_run) {
  base::FilePath local_state_path;
  PathService::Get(chrome::FILE_LOCAL_STATE, &local_state_path);
  bool local_state_file_exists = file_util::PathExists(local_state_path);

  // Load local state.  This includes the application locale so we know which
  // locale dll to load.  This also causes local state prefs to be registered.
  PrefService* local_state = g_browser_process->local_state();
  DCHECK(local_state);

  if (is_first_run) {
#if defined(OS_WIN)
    // During first run we read the google_update registry key to find what
    // language the user selected when downloading the installer. This
    // becomes our default language in the prefs.
    // Other platforms obey the system locale.
    std::wstring install_lang;
    if (GoogleUpdateSettings::GetLanguage(&install_lang)) {
      local_state->SetString(prefs::kApplicationLocale,
                             WideToASCII(install_lang));
    }
#endif  // defined(OS_WIN)
  }

  // If the local state file for the current profile doesn't exist and the
  // parent profile command line flag is present, then we should inherit some
  // local state from the parent profile.
  // Checking that the local state file for the current profile doesn't exist
  // is the most robust way to determine whether we need to inherit or not
  // since the parent profile command line flag can be present even when the
  // current profile is not a new one, and in that case we do not want to
  // inherit and reset the user's setting.
  //
  // TODO(mnissler): We should probably just instantiate a
  // JSONPrefStore here instead of an entire PrefService. Once this is
  // addressed, the call to browser_prefs::RegisterLocalState can move
  // to chrome_prefs::CreateLocalState.
  if (!local_state_file_exists &&
      parsed_command_line.HasSwitch(switches::kParentProfile)) {
    base::FilePath parent_profile =
        parsed_command_line.GetSwitchValuePath(switches::kParentProfile);
    scoped_refptr<PrefRegistrySimple> registry = new PrefRegistrySimple();
    scoped_ptr<PrefService> parent_local_state(
        chrome_prefs::CreateLocalState(
            parent_profile,
            local_state_task_runner,
            g_browser_process->policy_service(),
            NULL,
            registry,
            false));
    registry->RegisterStringPref(prefs::kApplicationLocale, std::string());
    // Right now, we only inherit the locale setting from the parent profile.
    local_state->SetString(
        prefs::kApplicationLocale,
        parent_local_state->GetString(prefs::kApplicationLocale));
  }

#if defined(OS_CHROMEOS)
  if (parsed_command_line.HasSwitch(switches::kLoginManager)) {
    std::string owner_locale = local_state->GetString(prefs::kOwnerLocale);
    // Ensure that we start with owner's locale.
    if (!owner_locale.empty() &&
        local_state->GetString(prefs::kApplicationLocale) != owner_locale &&
        !local_state->IsManagedPreference(prefs::kApplicationLocale)) {
      local_state->SetString(prefs::kApplicationLocale, owner_locale);
    }
  }
#endif

  return local_state;
}

// Returns the path that contains the profile that should be loaded
// on process startup.
base::FilePath GetStartupProfilePath(const base::FilePath& user_data_dir,
                                     const CommandLine& command_line) {
  if (command_line.HasSwitch(switches::kProfileDirectory)) {
    return user_data_dir.Append(
        command_line.GetSwitchValuePath(switches::kProfileDirectory));
  }

  // If we are showing the app list then chrome isn't shown so load the app
  // list's profile rather than chrome's.
  if (command_line.HasSwitch(switches::kShowAppList))
    return AppListService::Get()->GetAppListProfilePath(user_data_dir);

  return g_browser_process->profile_manager()->GetLastUsedProfileDir(
      user_data_dir);
}

// Initializes the profile, possibly doing some user prompting to pick a
// fallback profile. Returns the newly created profile, or NULL if startup
// should not continue.
Profile* CreateProfile(const content::MainFunctionParams& parameters,
                       const base::FilePath& user_data_dir,
                       const CommandLine& parsed_command_line) {
  if (ProfileManager::IsMultipleProfilesEnabled() &&
      parsed_command_line.HasSwitch(switches::kProfileDirectory)) {
    g_browser_process->local_state()->SetString(prefs::kProfileLastUsed,
        parsed_command_line.GetSwitchValueASCII(switches::kProfileDirectory));
    // Clear kProfilesLastActive since the user only wants to launch a specific
    // profile.
    ListPrefUpdate update(g_browser_process->local_state(),
                          prefs::kProfilesLastActive);
    ListValue* profile_list = update.Get();
    profile_list->Clear();
  }

  Profile* profile = NULL;
#if defined(OS_CHROMEOS)
  // TODO(ivankr): http://crbug.com/83792
  profile = g_browser_process->profile_manager()->GetDefaultProfile(
      user_data_dir);
#else
  base::FilePath profile_path =
      GetStartupProfilePath(user_data_dir, parsed_command_line);
  profile = g_browser_process->profile_manager()->GetProfile(
      profile_path);
#endif
  if (profile)
    return profile;

#if defined(OS_WIN)
#if defined(USE_AURA)
  // TODO(beng):
  NOTIMPLEMENTED();
#else
  // Ideally, we should be able to run w/o access to disk.  For now, we
  // prompt the user to pick a different user-data-dir and restart chrome
  // with the new dir.
  // http://code.google.com/p/chromium/issues/detail?id=11510
  base::FilePath new_user_data_dir =
      chrome::ShowUserDataDirDialog(user_data_dir);

  if (!new_user_data_dir.empty()) {
    // Because of the way CommandLine parses, it's sufficient to append a new
    // --user-data-dir switch.  The last flag of the same name wins.
    // TODO(tc): It would be nice to remove the flag we don't want, but that
    // sounds risky if we parse differently than CommandLineToArgvW.
    CommandLine new_command_line = parameters.command_line;
    new_command_line.AppendSwitchPath(switches::kUserDataDir,
                                      new_user_data_dir);
    base::LaunchProcess(new_command_line, base::LaunchOptions(), NULL);
  }
#endif
#else
  // TODO(port): fix this.  See comments near the definition of
  // user_data_dir.  It is better to CHECK-fail here than it is to
  // silently exit because of missing code in the above test.
  CHECK(profile) << "Cannot get default profile.";
#endif

  return NULL;
}

#if defined(OS_MACOSX)
OSStatus KeychainCallback(SecKeychainEvent keychain_event,
                          SecKeychainCallbackInfo* info, void* context) {
  return noErr;
}
#endif

// This code is specific to the Windows-only PreReadExperiment field-trial.
void AddPreReadHistogramTime(const char* name, base::TimeDelta time) {
  const base::TimeDelta kMin(base::TimeDelta::FromMilliseconds(1));
  const base::TimeDelta kMax(base::TimeDelta::FromHours(1));
  static const size_t kBuckets(100);

  // FactoryTimeGet will always return a pointer to the same histogram object,
  // keyed on its name. There's no need for us to store it explicitly anywhere.
  base::HistogramBase* counter = base::Histogram::FactoryTimeGet(
      name, kMin, kMax, kBuckets, base::Histogram::kUmaTargetedHistogramFlag);

  counter->AddTime(time);
}

void RecordDefaultBrowserUMAStat() {
  // Record whether Chrome is the default browser or not.
  ShellIntegration::DefaultWebClientState default_state =
      ShellIntegration::GetDefaultBrowser();
  UMA_HISTOGRAM_ENUMERATION("DefaultBrowser.State", default_state,
                            ShellIntegration::NUM_DEFAULT_STATES);
}

void RecordTouchEventState(const CommandLine& command_line) {
  const std::string touch_enabled_switch =
      command_line.HasSwitch(switches::kTouchEvents) ?
      command_line.GetSwitchValueASCII(switches::kTouchEvents) :
      switches::kTouchEventsAuto;

  if (touch_enabled_switch.empty() ||
      touch_enabled_switch == switches::kTouchEventsEnabled) {
    UMA_HISTOGRAM_ENUMERATION("Touchscreen.TouchEventsEnabled",
                              UMA_TOUCH_EVENTS_ENABLED,
                              UMA_TOUCH_EVENTS_STATE_COUNT);
  } else if (touch_enabled_switch == switches::kTouchEventsAuto) {
    bool touch_device_present = ui::IsTouchDevicePresent();
    UMA_HISTOGRAM_ENUMERATION("Touchscreen.TouchEventsEnabled",
                              touch_device_present ?
                                  UMA_TOUCH_EVENTS_AUTO_ENABLED :
                                  UMA_TOUCH_EVENTS_AUTO_DISABLED,
                              UMA_TOUCH_EVENTS_STATE_COUNT);
  } else if (touch_enabled_switch == switches::kTouchEventsDisabled) {
    UMA_HISTOGRAM_ENUMERATION("Touchscreen.TouchEventsEnabled",
                              UMA_TOUCH_EVENTS_DISABLED,
                              UMA_TOUCH_EVENTS_STATE_COUNT);
  }
}

void RegisterComponentsForUpdate(const CommandLine& command_line) {
  ComponentUpdateService* cus = g_browser_process->component_updater();
  if (!cus)
    return;
  // Registration can be before of after cus->Start() so it is ok to post
  // a task to the UI thread to do registration once you done the necessary
  // file IO to know you existing component version.
  RegisterRecoveryComponent(cus, g_browser_process->local_state());
  RegisterPepperFlashComponent(cus);
  RegisterSwiftShaderComponent(cus);

  // CRLSetFetcher attempts to load a CRL set from either the local disk or
  // network.
  if (!command_line.HasSwitch(switches::kDisableCRLSets))
    g_browser_process->crl_set_fetcher()->StartInitialLoad(cus);

  RegisterPnaclComponent(cus, command_line);

  cus->Start();
}

bool ProcessSingletonNotificationCallback(
    const CommandLine& command_line,
    const base::FilePath& current_directory) {
  // Drop the request if the browser process is already in shutdown path.
  if (!g_browser_process || g_browser_process->IsShuttingDown())
    return false;

  g_browser_process->PlatformSpecificCommandLineProcessing(command_line);

  // TODO(erikwright): Consider removing this - AFAIK it is no longer used.
  // Handle the --uninstall-extension startup action. This needs to done here
  // in the process that is running with the target profile, otherwise the
  // uninstall will fail to unload and remove all components.
  if (command_line.HasSwitch(switches::kUninstallExtension)) {
    // The uninstall extension switch can't be combined with the profile
    // directory switch.
    DCHECK(!command_line.HasSwitch(switches::kProfileDirectory));

    Profile* profile = ProfileManager::GetLastUsedProfile();
    if (!profile) {
      // We should never be called before the profile has been created.
      NOTREACHED();
      return true;
    }

    extensions::StartupHelper extension_startup_helper;
    extension_startup_helper.UninstallExtension(command_line, profile);
    return true;
  }

  base::FilePath user_data_dir =
      g_browser_process->profile_manager()->user_data_dir();
  base::FilePath startup_profile_dir =
      GetStartupProfilePath(user_data_dir, command_line);

  StartupBrowserCreator::ProcessCommandLineAlreadyRunning(
      command_line, current_directory, startup_profile_dir);
  return true;
}

void LaunchDevToolsHandlerIfNeeded(Profile* profile,
                                   const CommandLine& command_line) {
  if (command_line.HasSwitch(::switches::kRemoteDebuggingPort)) {
    std::string port_str =
        command_line.GetSwitchValueASCII(::switches::kRemoteDebuggingPort);
    int port;
    if (base::StringToInt(port_str, &port) && port > 0 && port < 65535) {
      std::string frontend_str;
      if (command_line.HasSwitch(::switches::kRemoteDebuggingFrontend)) {
        frontend_str = command_line.GetSwitchValueASCII(
            ::switches::kRemoteDebuggingFrontend);
      }
      g_browser_process->CreateDevToolsHttpProtocolHandler(
          profile,
          chrome::HOST_DESKTOP_TYPE_NATIVE,
          "127.0.0.1",
          port,
          frontend_str);
    } else {
      DLOG(WARNING) << "Invalid http debugger port number " << port;
    }
  }
}

// Heap allocated class that listens for first page load, kicks off stat
// recording and then deletes itself.
class LoadCompleteListener : public content::NotificationObserver {
 public:
   LoadCompleteListener() {
     registrar_.Add(this,
                    content::NOTIFICATION_LOAD_COMPLETED_MAIN_FRAME,
                    content::NotificationService::AllSources());
   }
   virtual ~LoadCompleteListener() {}

   // content::NotificationObserver implementation.
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE {
     DCHECK(type == content::NOTIFICATION_LOAD_COMPLETED_MAIN_FRAME);
     startup_metric_utils::OnInitialPageLoadComplete();
     delete this;
   }

 private:
  content::NotificationRegistrar registrar_;
  DISALLOW_COPY_AND_ASSIGN(LoadCompleteListener);
};

}  // namespace

namespace chrome_browser {
// This error message is not localized because we failed to load the
// localization data files.
const char kMissingLocaleDataTitle[] = "Missing File Error";
const char kMissingLocaleDataMessage[] =
    "Unable to find locale data files. Please reinstall.";
}  // namespace chrome_browser

// BrowserMainParts ------------------------------------------------------------

// static
bool ChromeBrowserMainParts::disable_enforcing_cookie_policies_for_tests_ =
    false;

ChromeBrowserMainParts::ChromeBrowserMainParts(
    const content::MainFunctionParams& parameters)
    : parameters_(parameters),
      parsed_command_line_(parameters.command_line),
      result_code_(content::RESULT_CODE_NORMAL_EXIT),
      startup_watcher_(new StartupTimeBomb()),
      shutdown_watcher_(new ShutdownWatcherHelper()),
      startup_timer_(new performance_monitor::StartupTimer()),
      browser_field_trials_(parameters.command_line),
      record_search_engine_(false),
      translate_manager_(NULL),
      profile_(NULL),
      run_message_loop_(true),
      notify_result_(ProcessSingleton::PROCESS_NONE),
      do_first_run_tasks_(false),
      local_state_(NULL),
      restart_last_session_(false) {
  // If we're running tests (ui_task is non-null).
  if (parameters.ui_task)
    browser_defaults::enable_help_app = false;

  // Chrome disallows cookies by default. All code paths that want to use
  // cookies need to go through one of Chrome's URLRequestContexts which have
  // a ChromeNetworkDelegate attached that selectively allows cookies again.
  if (!disable_enforcing_cookie_policies_for_tests_)
    net::URLRequest::SetDefaultCookiePolicyToBlock();
}

ChromeBrowserMainParts::~ChromeBrowserMainParts() {
  for (int i = static_cast<int>(chrome_extra_parts_.size())-1; i >= 0; --i)
    delete chrome_extra_parts_[i];
  chrome_extra_parts_.clear();
}

// This will be called after the command-line has been mutated by about:flags
void ChromeBrowserMainParts::SetupMetricsAndFieldTrials() {
  // Must initialize metrics after labs have been converted into switches,
  // but before field trials are set up (so that client ID is available for
  // one-time randomized field trials).
#if defined(OS_WIN)
  if (parsed_command_line_.HasSwitch(switches::kChromeFrame))
    MetricsLog::set_version_extension("-F");
#elif defined(ARCH_CPU_64_BITS)
  MetricsLog::set_version_extension("-64");
#elif defined(OS_ANDROID)
  // Set version extension to identify Android releases.
  // Example: 16.0.912.61-K88
  std::string version_extension = "-K";
  version_extension.append(
      base::android::BuildInfo::GetInstance()->package_version_code());
  MetricsLog::set_version_extension(version_extension);
#endif  // defined(OS_WIN)

  // Initialize FieldTrialList to support FieldTrials that use one-time
  // randomization.
  MetricsService* metrics = browser_process_->metrics_service();
  bool metrics_reporting_enabled = IsMetricsReportingEnabled();
  if (metrics_reporting_enabled)
    metrics->ForceClientIdCreation();  // Needed below.
  field_trial_list_.reset(
      new base::FieldTrialList(
          metrics->CreateEntropyProvider(metrics_reporting_enabled).release()));

  // Ensure any field trials specified on the command line are initialized.
  // Also stop the metrics service so that we don't pollute UMA.
  const CommandLine* command_line = CommandLine::ForCurrentProcess();
  if (command_line->HasSwitch(switches::kForceFieldTrials)) {
    std::string persistent = command_line->GetSwitchValueASCII(
        switches::kForceFieldTrials);
    bool ret = base::FieldTrialList::CreateTrialsFromString(persistent);
    CHECK(ret) << "Invalid --" << switches::kForceFieldTrials <<
                  " list specified.";
  }

  chrome_variations::VariationsService* variations_service =
      browser_process_->variations_service();
  if (variations_service)
    variations_service->CreateTrialsFromSeed();

  const int64 install_date = local_state_->GetInt64(prefs::kInstallDate);
  // This must be called after the pref is initialized.
  DCHECK(install_date);
  browser_field_trials_.SetupFieldTrials(base::Time::FromTimeT(install_date));

  SetupPlatformFieldTrials();

  // Initialize FieldTrialSynchronizer system. This is a singleton and is used
  // for posting tasks via base::Bind. Its deleted when it goes out of scope.
  // Even though base::Bind does AddRef and Release, the object will not be
  // deleted after the Task is executed.
  field_trial_synchronizer_ = new FieldTrialSynchronizer();
}

// ChromeBrowserMainParts: |SetupMetricsAndFieldTrials()| related --------------

void ChromeBrowserMainParts::StartMetricsRecording() {
  MetricsService* metrics = g_browser_process->metrics_service();

  const bool enable_benchmarking =
      parsed_command_line_.HasSwitch(switches::kEnableBenchmarking);
  // TODO(stevet): This is a temporary histogram used to investigate an issue
  // with logging. Remove this when investigations are complete.
  UMA_HISTOGRAM_BOOLEAN("UMA.FieldTrialsEnabledBenchmarking",
                        enable_benchmarking);
  // TODO(miu): Metrics reporting is disabled in DEBUG builds until ill-fired
  // DCHECKs are fixed, and/or we reconsider whether metrics reporting should
  // really ever be enabled for debug builds.  http://crbug.com/156979
#if defined(NDEBUG)
  const bool only_do_metrics_recording = enable_benchmarking ||
      parsed_command_line_.HasSwitch(switches::kMetricsRecordingOnly);
#else
  const bool only_do_metrics_recording = true;
#endif
  if (only_do_metrics_recording) {
    // If we're testing then we don't care what the user preference is, we turn
    // on recording, but not reporting, otherwise tests fail.
    metrics->StartRecordingForTests();
    return;
  }

  if (IsMetricsReportingEnabled())
    metrics->Start();
}

bool ChromeBrowserMainParts::IsMetricsReportingEnabled() {
  // If the user permits metrics reporting with the checkbox in the
  // prefs, we turn on recording.  We disable metrics completely for
  // non-official builds.  This can be forced with a flag.
  const CommandLine* command_line = CommandLine::ForCurrentProcess();
  if (command_line->HasSwitch(switches::kEnableMetricsReportingForTesting))
    return true;

  bool enabled = false;
  // The debug build doesn't send UMA logs when FieldTrials are forced.
  if (command_line->HasSwitch(switches::kForceFieldTrials))
    return false;

#if defined(GOOGLE_CHROME_BUILD)
#if defined(OS_CHROMEOS)
  chromeos::CrosSettings::Get()->GetBoolean(chromeos::kStatsReportingPref,
                                            &enabled);
#else
  enabled = local_state_->GetBoolean(prefs::kMetricsReportingEnabled);
#endif  // #if defined(OS_CHROMEOS)
#endif  // defined(GOOGLE_CHROME_BUILD)
  return enabled;
}

// -----------------------------------------------------------------------------
// TODO(viettrungluu): move more/rest of BrowserMain() into BrowserMainParts.

#if defined(OS_WIN)
#define DLLEXPORT __declspec(dllexport)

// We use extern C for the prototype DLLEXPORT to avoid C++ name mangling.
extern "C" {
DLLEXPORT void __cdecl RelaunchChromeBrowserWithNewCommandLineIfNeeded();
}

DLLEXPORT void __cdecl RelaunchChromeBrowserWithNewCommandLineIfNeeded() {
  // Need an instance of AtExitManager to handle singleton creations and
  // deletions.  We need this new instance because, the old instance created
  // in ChromeMain() got destructed when the function returned.
  base::AtExitManager exit_manager;
  upgrade_util::RelaunchChromeBrowserWithNewCommandLineIfNeeded();
}
#endif

// content::BrowserMainParts implementation ------------------------------------

void ChromeBrowserMainParts::PreEarlyInitialization() {
  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
    chrome_extra_parts_[i]->PreEarlyInitialization();
}

void ChromeBrowserMainParts::PostEarlyInitialization() {
  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
    chrome_extra_parts_[i]->PostEarlyInitialization();
}

void ChromeBrowserMainParts::ToolkitInitialized() {
  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
    chrome_extra_parts_[i]->ToolkitInitialized();
}

void ChromeBrowserMainParts::PreMainMessageLoopStart() {
  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
    chrome_extra_parts_[i]->PreMainMessageLoopStart();
}

void ChromeBrowserMainParts::PostMainMessageLoopStart() {
  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
    chrome_extra_parts_[i]->PostMainMessageLoopStart();
}

int ChromeBrowserMainParts::PreCreateThreads() {
  result_code_ = PreCreateThreadsImpl();
  // These members must be initialized before returning from this function.
  DCHECK(master_prefs_.get());
#if !defined(OS_ANDROID)
  DCHECK(browser_creator_.get());
#endif
  return result_code_;
}

int ChromeBrowserMainParts::PreCreateThreadsImpl() {
  run_message_loop_ = false;
#if defined(OS_WIN)
  PathService::Get(chrome::DIR_USER_DATA, &user_data_dir_);
#else
  // Getting the user data dir can fail if the directory isn't
  // creatable, for example; on Windows in code below we bring up a
  // dialog prompting the user to pick a different directory.
  // However, ProcessSingleton needs a real user_data_dir on Mac/Linux,
  // so it's better to fail here than fail mysteriously elsewhere.
  CHECK(PathService::Get(chrome::DIR_USER_DATA, &user_data_dir_))
      << "Must be able to get user data directory!";
#endif

  // Whether this is First Run. |do_first_run_tasks_| should be prefered to this
  // unless the desire is actually to know whether this is really First Run
  // (i.e., even if --no-first-run is passed).
  bool is_first_run = false;
  // Android's first run is done in Java instead of native.
#if !defined(OS_ANDROID)

  process_singleton_.reset(new ProcessSingleton(user_data_dir_));
  // Ensure ProcessSingleton won't process messages too early. It will be
  // unlocked in PostBrowserStart().
  process_singleton_->Lock(NULL);

  bool force_first_run =
      parsed_command_line().HasSwitch(switches::kForceFirstRun);
  bool force_skip_first_run_tasks =
      (!force_first_run &&
       parsed_command_line().HasSwitch(switches::kNoFirstRun));

  is_first_run =
      (force_first_run || first_run::IsChromeFirstRun()) &&
      !ProfileManager::IsImportProcess(parsed_command_line());
#endif

  scoped_refptr<base::SequencedTaskRunner> local_state_task_runner =
      JsonPrefStore::GetTaskRunnerForFile(
          base::FilePath(chrome::kLocalStorePoolName),
          BrowserThread::GetBlockingPool());
  browser_process_.reset(new BrowserProcessImpl(local_state_task_runner,
                                                parsed_command_line()));

  if (parsed_command_line().HasSwitch(switches::kEnableProfiling)) {
    // User wants to override default tracking status.
    std::string flag =
      parsed_command_line().GetSwitchValueASCII(switches::kEnableProfiling);
    // Default to basic profiling (no parent child support).
    tracked_objects::ThreadData::Status status =
          tracked_objects::ThreadData::PROFILING_ACTIVE;
    if (flag.compare("0") != 0)
      status = tracked_objects::ThreadData::DEACTIVATED;
    else if (flag.compare("child") != 0)
      status = tracked_objects::ThreadData::PROFILING_CHILDREN_ACTIVE;
    tracked_objects::ThreadData::InitializeAndSetTrackingStatus(status);
  }

  if (parsed_command_line().HasSwitch(switches::kProfilingOutputFile)) {
    tracking_objects_.set_output_file_path(
        parsed_command_line().GetSwitchValuePath(
            switches::kProfilingOutputFile));
  }

  local_state_ = InitializeLocalState(local_state_task_runner,
                                      parsed_command_line(),
                                      is_first_run);

  // These members must be initialized before returning from this function.
  master_prefs_.reset(new first_run::MasterPrefs);

#if !defined(OS_ANDROID)
  // Android doesn't use StartupBrowserCreator.
  browser_creator_.reset(new StartupBrowserCreator);
  // TODO(yfriedman): Refactor Android to re-use UMABrowsingActivityObserver
  chrome::UMABrowsingActivityObserver::Init();
#endif

  // Convert active labs into switches. This needs to be done before
  // ResourceBundle::InitSharedInstanceWithLocale as some loaded resources are
  // affected by experiment flags (--touch-optimized-ui in particular). Not
  // needed on Android as there aren't experimental flags.
  about_flags::ConvertFlagsToSwitches(local_state_,
                                      CommandLine::ForCurrentProcess());
  local_state_->UpdateCommandLinePrefStore(
      new CommandLinePrefStore(CommandLine::ForCurrentProcess()));

  // Reset the command line in the crash report details, since we may have
  // just changed it to include experiments.
  child_process_logging::SetCommandLine(CommandLine::ForCurrentProcess());

  // If we're running tests (ui_task is non-null), then the ResourceBundle
  // has already been initialized.
  if (parameters().ui_task &&
      !local_state_->IsManagedPreference(prefs::kApplicationLocale)) {
    browser_process_->SetApplicationLocale("en-US");
  } else {
    // Mac starts it earlier in |PreMainMessageLoopStart()| (because it is
    // needed when loading the MainMenu.nib and the language doesn't depend on
    // anything since it comes from Cocoa.
#if defined(OS_MACOSX)
    browser_process_->SetApplicationLocale(l10n_util::GetLocaleOverride());
#else
    const std::string locale =
        local_state_->GetString(prefs::kApplicationLocale);
    // On a POSIX OS other than ChromeOS, the parameter that is passed to the
    // method InitSharedInstance is ignored.
    const std::string loaded_locale =
        ResourceBundle::InitSharedInstanceWithLocale(locale, NULL);
    if (loaded_locale.empty() &&
        !parsed_command_line().HasSwitch(switches::kNoErrorDialogs)) {
      ShowMissingLocaleMessageBox();
      return chrome::RESULT_CODE_MISSING_DATA;
    }
    CHECK(!loaded_locale.empty()) << "Locale could not be found for " << locale;
    browser_process_->SetApplicationLocale(loaded_locale);

    base::FilePath resources_pack_path;
    PathService::Get(chrome::FILE_RESOURCES_PACK, &resources_pack_path);
    ResourceBundle::GetSharedInstance().AddDataPackFromPath(
        resources_pack_path, ui::SCALE_FACTOR_NONE);
#endif  // defined(OS_MACOSX)
  }

#if defined(TOOLKIT_GTK)
  g_set_application_name(l10n_util::GetStringUTF8(IDS_PRODUCT_NAME).c_str());
#endif

  // Android does first run in Java instead of native.
#if !defined(OS_ANDROID)
  // On first run, we need to process the predictor preferences before the
  // browser's profile_manager object is created, but after ResourceBundle
  // is initialized.
  if (is_first_run) {
    first_run::ProcessMasterPreferencesResult pmp_result =
        first_run::ProcessMasterPreferences(user_data_dir_,
                                            master_prefs_.get());
    if (pmp_result == first_run::EULA_EXIT_NOW)
      return chrome::RESULT_CODE_EULA_REFUSED;

    // Do first run tasks unless:
    //  - Explicitly forced not to by |force_skip_first_run_tasks| or
    //    |pmp_result|.
    //  - Running in App (or App Launcher) mode, where showing the importer
    //    (first run) UI is undesired.
    do_first_run_tasks_ = (
        !force_skip_first_run_tasks &&
        pmp_result != first_run::SKIP_FIRST_RUN_TASKS &&
        !parsed_command_line().HasSwitch(switches::kApp) &&
        !parsed_command_line().HasSwitch(switches::kAppId) &&
        !parsed_command_line().HasSwitch(switches::kShowAppList));

    if (do_first_run_tasks_) {
      AddFirstRunNewTabs(browser_creator_.get(), master_prefs_->new_tabs);

      // Store the initial VariationsService seed in local state, if it exists
      // in master prefs.
      if (!master_prefs_->variations_seed.empty()) {
        local_state_->SetString(prefs::kVariationsSeed,
                                master_prefs_->variations_seed);
        // Set the variation seed date to the current system time. If the user's
        // clock is incorrect, this may cause some field trial expiry checks to
        // not do the right thing until the next seed update from the server,
        // when this value will be updated.
        local_state_->SetInt64(prefs::kVariationsSeedDate,
                               base::Time::Now().ToInternalValue());
      }
    } else if (parsed_command_line().HasSwitch(switches::kNoFirstRun)) {
      // Create the First Run beacon anyways if --no-first-run was passed on the
      // command line.
      first_run::CreateSentinel();
    }
  }
#endif

  // TODO(viettrungluu): why don't we run this earlier?
  if (!parsed_command_line().HasSwitch(switches::kNoErrorDialogs))
    WarnAboutMinimumSystemRequirements();

#if defined(OS_LINUX) || defined(OS_OPENBSD) || defined(OS_MACOSX)
  // Set the product channel for crash reports.
  child_process_logging::SetChannel(
      chrome::VersionInfo::GetVersionStringModifier());
#endif

  // Initialize tracking synchronizer system.
  tracking_synchronizer_ = new chrome_browser_metrics::TrackingSynchronizer();

  // Now that all preferences have been registered, set the install date
  // for the uninstall metrics if this is our first run. This only actually
  // gets used if the user has metrics reporting enabled at uninstall time.
  int64 install_date = local_state_->GetInt64(prefs::kInstallDate);
  if (install_date == 0)
    local_state_->SetInt64(prefs::kInstallDate, base::Time::Now().ToTimeT());

#if defined(OS_MACOSX)
  // Get the Keychain API to register for distributed notifications on the main
  // thread, which has a proper CFRunloop, instead of later on the I/O thread,
  // which doesn't. This ensures those notifications will get delivered
  // properly. See issue 37766.
  // (Note that the callback mask here is empty. I don't want to register for
  // any callbacks, I just want to initialize the mechanism.)
  SecKeychainAddCallback(&KeychainCallback, 0, NULL);
#endif

  // Now the command line has been mutated based on about:flags, we can setup
  // metrics and initialize field trials. The field trials are needed by
  // IOThread's initialization which happens in BrowserProcess:PreCreateThreads.
  SetupMetricsAndFieldTrials();

  // ChromeOS needs ResourceBundle::InitSharedInstance to be called before this.
  browser_process_->PreCreateThreads();

  return content::RESULT_CODE_NORMAL_EXIT;
}

void ChromeBrowserMainParts::PreMainMessageLoopRun() {
  result_code_ = PreMainMessageLoopRunImpl();

  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
    chrome_extra_parts_[i]->PreMainMessageLoopRun();
}

// PreMainMessageLoopRun calls these extra stages in the following order:
//  PreMainMessageLoopRunImpl()
//   ... initial setup, including browser_process_ setup.
//   PreProfileInit()
//   ... additional setup, including CreateProfile()
//   PostProfileInit()
//   ... additional setup
//   PreBrowserStart()
//   ... browser_creator_->Start (OR parameters().ui_task->Run())
//   PostBrowserStart()

void ChromeBrowserMainParts::PreProfileInit() {
  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
    chrome_extra_parts_[i]->PreProfileInit();
}

void ChromeBrowserMainParts::PostProfileInit() {
  LaunchDevToolsHandlerIfNeeded(profile(), parsed_command_line());
  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
    chrome_extra_parts_[i]->PostProfileInit();
}

void ChromeBrowserMainParts::PreBrowserStart() {
  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
    chrome_extra_parts_[i]->PreBrowserStart();
#if !defined(OS_ANDROID)
  gpu_util::InstallBrowserMonitor();
#endif

  three_d_observer_.reset(new ThreeDAPIObserver());
}

void ChromeBrowserMainParts::PostBrowserStart() {
#if !defined(OS_ANDROID)
  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kVisitURLs))
    RunPageCycler();
#endif

  // Create the instance of the Google Now service.
#if defined(ENABLE_GOOGLE_NOW)
  if (CommandLine::ForCurrentProcess()->HasSwitch(
      switches::kEnableGoogleNowIntegration)) {
    GoogleNowServiceFactory::GetForProfile(profile_);
  }
#endif

  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
    chrome_extra_parts_[i]->PostBrowserStart();
#if !defined(OS_ANDROID)
  // Allow ProcessSingleton to process messages.
  process_singleton_->Unlock();
#endif
}

#if !defined(OS_ANDROID)
void ChromeBrowserMainParts::RunPageCycler() {
  CommandLine* command_line = CommandLine::ForCurrentProcess();
  // We assume a native desktop for tests, but we will need to find a way to
  // get the proper host desktop type once we start running these tests in ASH.
  Browser* browser = chrome::FindBrowserWithProfile(
      profile_, chrome::HOST_DESKTOP_TYPE_NATIVE);
  DCHECK(browser);
  PageCycler* page_cycler = NULL;
  base::FilePath input_file =
      command_line->GetSwitchValuePath(switches::kVisitURLs);
  page_cycler = new PageCycler(browser, input_file);
  page_cycler->set_errors_file(
      input_file.AddExtension(FILE_PATH_LITERAL(".errors")));
  if (command_line->HasSwitch(switches::kRecordStats)) {
    page_cycler->set_stats_file(
        command_line->GetSwitchValuePath(switches::kRecordStats));
  }
  page_cycler->Run();
}
#endif   // !defined(OS_ANDROID)

void ChromeBrowserMainParts::SetupPlatformFieldTrials() {
  // Base class implementation of this does nothing.
}

int ChromeBrowserMainParts::PreMainMessageLoopRunImpl() {
  // Android updates the metrics service dynamically depending on whether the
  // application is in the foreground or not. Do not start here.
#if !defined(OS_ANDROID)
  // Now that the file thread has been started, start recording.
  StartMetricsRecording();
#endif

#if defined(ARCH_CPU_X86_FAMILY)
  LogIntelMicroArchitecture();
#endif  // defined(ARCH_CPU_X86_FAMILY)

  // Create watchdog thread after creating all other threads because it will
  // watch the other threads and they must be running.
  browser_process_->watchdog_thread();

  // Do any initializating in the browser process that requires all threads
  // running.
  browser_process_->PreMainMessageLoopRun();

  // Record last shutdown time into a histogram.
  browser_shutdown::ReadLastShutdownInfo();

#if defined(OS_WIN)
  // On Windows, we use our startup as an opportunity to do upgrade/uninstall
  // tasks.  Those care whether the browser is already running.  On Linux/Mac,
  // upgrade/uninstall happen separately.
  bool already_running = browser_util::IsBrowserAlreadyRunning();

  // If the command line specifies 'uninstall' then we need to work here
  // unless we detect another chrome browser running.
  if (parsed_command_line().HasSwitch(switches::kUninstall)) {
    return DoUninstallTasks(already_running);
  }

  if (parsed_command_line().HasSwitch(switches::kHideIcons) ||
      parsed_command_line().HasSwitch(switches::kShowIcons)) {
    return ChromeBrowserMainPartsWin::HandleIconsCommands(
        parsed_command_line_);
  }
#endif

  if (parsed_command_line().HasSwitch(switches::kMakeDefaultBrowser)) {
    return ShellIntegration::SetAsDefaultBrowser() ?
        static_cast<int>(content::RESULT_CODE_NORMAL_EXIT) :
        static_cast<int>(chrome::RESULT_CODE_SHELL_INTEGRATION_FAILED);
  }

  // Android doesn't support extensions and doesn't implement ProcessSingleton.
#if !defined(OS_ANDROID)
  // If the command line specifies --pack-extension, attempt the pack extension
  // startup action and exit.
  if (parsed_command_line().HasSwitch(switches::kPackExtension)) {
    extensions::StartupHelper extension_startup_helper;
    if (extension_startup_helper.PackExtension(parsed_command_line()))
      return content::RESULT_CODE_NORMAL_EXIT;
    return chrome::RESULT_CODE_PACK_EXTENSION_ERROR;
  }

  bool pass_command_line = true;

#if !defined(OS_MACOSX)
  // In environments other than Mac OS X we support import of settings
  // from other browsers. In case this process is a short-lived "import"
  // process that another browser runs just to import the settings, we
  // don't want to be checking for another browser process, by design.
  pass_command_line = !ProfileManager::IsImportProcess(parsed_command_line());
#endif

  // If we're being launched just to check the connector policy, we are
  // short-lived and don't want to be passing that switch off.
  pass_command_line = pass_command_line && !parsed_command_line().HasSwitch(
      switches::kCheckCloudPrintConnectorPolicy);

  if (pass_command_line) {
    // When another process is running, use that process instead of starting a
    // new one. NotifyOtherProcess will currently give the other process up to
    // 20 seconds to respond. Note that this needs to be done before we attempt
    // to read the profile.
    notify_result_ = process_singleton_->NotifyOtherProcessOrCreate(
        base::Bind(&ProcessSingletonNotificationCallback));
    UMA_HISTOGRAM_ENUMERATION("NotifyOtherProcessOrCreate.Result",
                               notify_result_,
                               ProcessSingleton::NUM_NOTIFY_RESULTS);
    switch (notify_result_) {
      case ProcessSingleton::PROCESS_NONE:
        // No process already running, fall through to starting a new one.
        break;

      case ProcessSingleton::PROCESS_NOTIFIED:
#if defined(OS_POSIX) && !defined(OS_MACOSX)
        printf("%s\n", base::SysWideToNativeMB(UTF16ToWide(
            l10n_util::GetStringUTF16(IDS_USED_EXISTING_BROWSER))).c_str());
#endif
        // Having a differentiated return type for testing allows for tests to
        // verify proper handling of some switches. When not testing, stick to
        // the standard Unix convention of returning zero when things went as
        // expected.
        if (parsed_command_line().HasSwitch(switches::kTestType))
          return chrome::RESULT_CODE_NORMAL_EXIT_PROCESS_NOTIFIED;
        return content::RESULT_CODE_NORMAL_EXIT;

      case ProcessSingleton::PROFILE_IN_USE:
        return chrome::RESULT_CODE_PROFILE_IN_USE;

      case ProcessSingleton::LOCK_ERROR:
        LOG(ERROR) << "Failed to create a ProcessSingleton for your profile "
                      "directory. This means that running multiple instances "
                      "would start multiple browser processes rather than "
                      "opening a new window in the existing process. Aborting "
                      "now to avoid profile corruption.";
        return chrome::RESULT_CODE_PROFILE_IN_USE;

      default:
        NOTREACHED();
    }
  }
#endif  // !defined(OS_ANDROID)

#if defined(USE_X11)
  SetBrowserX11ErrorHandlers();
#endif

  // Desktop construction occurs here, (required before profile creation).
  PreProfileInit();

  std::string try_chrome =
      parsed_command_line().GetSwitchValueASCII(switches::kTryChromeAgain);
  if (!try_chrome.empty()) {
#if defined(OS_WIN)
    // Setup.exe has determined that we need to run a retention experiment
    // and has lauched chrome to show the experiment UI. It is guaranteed that
    // no other Chrome is currently running as the process singleton was
    // sucessfully grabbed above.
    int try_chrome_int;
    base::StringToInt(try_chrome, &try_chrome_int);
    TryChromeDialogView::Result answer =
        TryChromeDialogView::Show(try_chrome_int, process_singleton_.get());
    if (answer == TryChromeDialogView::NOT_NOW)
      return chrome::RESULT_CODE_NORMAL_EXIT_CANCEL;
    if (answer == TryChromeDialogView::UNINSTALL_CHROME)
      return chrome::RESULT_CODE_NORMAL_EXIT_EXP2;
    // At this point the user is willing to try chrome again.
    if (answer == TryChromeDialogView::TRY_CHROME_AS_DEFAULT) {
      // Only set in the unattended case, the interactive case is Windows 8.
      if (ShellIntegration::CanSetAsDefaultBrowser() ==
          ShellIntegration::SET_DEFAULT_UNATTENDED)
        ShellIntegration::SetAsDefaultBrowser();
    }
#else
    // We don't support retention experiments on Mac or Linux.
    return content::RESULT_CODE_NORMAL_EXIT;
#endif  // defined(OS_WIN)
  }

  // Profile creation ----------------------------------------------------------

  if (do_first_run_tasks_) {
    // Warn the ProfileManager that an import process will run, possibly
    // locking the WebDataService directory of the next Profile created.
    browser_process_->profile_manager()->SetWillImport();
  }

  profile_ = CreateProfile(parameters(), user_data_dir_, parsed_command_line());
  if (!profile_)
    return content::RESULT_CODE_NORMAL_EXIT;

#if defined(ENABLE_BACKGROUND)
  // Autoload any profiles which are running background apps.
  // TODO(rlp): Do this on a separate thread. See http://crbug.com/99075.
  browser_process_->profile_manager()->AutoloadProfiles();
#endif
  // Post-profile init ---------------------------------------------------------

#if !defined(OS_MACOSX) && !defined(OS_ANDROID)
  // Importing other browser settings is done in a browser-like process
  // that exits when this task has finished.
  // TODO(port): Port the Mac's IPC-based implementation to other platforms to
  //             replace this implementation. http://crbug.com/22142
  if (ProfileManager::IsImportProcess(parsed_command_line())) {
    return first_run::ImportNow(profile_, parsed_command_line());
  }
#endif

#if defined(OS_WIN)
  // Do the tasks if chrome has been upgraded while it was last running.
  if (!already_running && upgrade_util::DoUpgradeTasks(parsed_command_line()))
    return content::RESULT_CODE_NORMAL_EXIT;

  // Check if there is any machine level Chrome installed on the current
  // machine. If yes and the current Chrome process is user level, we do not
  // allow the user level Chrome to run. So we notify the user and uninstall
  // user level Chrome.
  // Note this check should only happen here, after all the checks above
  // (uninstall, resource bundle initialization, other chrome browser
  // processes etc).
  // Do not allow this to occur for Chrome Frame user-to-system handoffs.
  if (!parsed_command_line().HasSwitch(switches::kChromeFrame) &&
      ChromeBrowserMainPartsWin::CheckMachineLevelInstall()) {
    return chrome::RESULT_CODE_MACHINE_LEVEL_INSTALL_EXISTS;
  }
#endif

  // Create the TranslateManager singleton.
  translate_manager_ = TranslateManager::GetInstance();
  DCHECK(translate_manager_ != NULL);

#if !defined(OS_ANDROID)
  // Initialize Managed Mode.
  ManagedMode::Init(profile_);
#endif

  // Needs to be done before PostProfileInit, since login manager on CrOS is
  // called inside PostProfileInit.
  content::WebUIControllerFactory::RegisterFactory(
      ChromeWebUIControllerFactory::GetInstance());

  // TODO(stevenjb): Move WIN and MACOSX specific code to appropriate Parts.
  // (requires supporting early exit).
  PostProfileInit();

  // Retrieve cached GL strings from local state and use them for GPU
  // blacklist decisions.
  if (g_browser_process->gl_string_manager())
    g_browser_process->gl_string_manager()->Initialize();

#if !defined(OS_ANDROID)
  // Show the First Run UI if this is the first time Chrome has been run on
  // this computer, or we're being compelled to do so by a command line flag.
  // Note that this be done _after_ the PrefService is initialized and all
  // preferences are registered, since some of the code that the importer
  // touches reads preferences.
  if (do_first_run_tasks_) {
    first_run::AutoImport(profile_,
                          master_prefs_->homepage_defined,
                          master_prefs_->do_import_items,
                          master_prefs_->dont_import_items,
                          process_singleton_.get());
    // Note: this can pop the first run consent dialog on linux.
    first_run::DoPostImportTasks(profile_, master_prefs_->make_chrome_default);

    browser_process_->profile_manager()->OnImportFinished(profile_);

    if (!master_prefs_->suppress_first_run_default_browser_prompt) {
      browser_creator_->set_show_main_browser_window(
          !chrome::ShowFirstRunDefaultBrowserPrompt(profile_));
    } else {
      browser_creator_->set_is_default_browser_dialog_suppressed(true);
    }
  }  // if (do_first_run_tasks_)
#endif  // !defined(OS_ANDROID)

#if defined(OS_WIN)
  // Sets things up so that if we crash from this point on, a dialog will
  // popup asking the user to restart chrome. It is done this late to avoid
  // testing against a bunch of special cases that are taken care early on.
  ChromeBrowserMainPartsWin::PrepareRestartOnCrashEnviroment(
      parsed_command_line());

  // Registers Chrome with the Windows Restart Manager, which will restore the
  // Chrome session when the computer is restarted after a system update.
  // This could be run as late as WM_QUERYENDSESSION for system update reboots,
  // but should run on startup if extended to handle crashes/hangs/patches.
  // Also, better to run once here than once for each HWND's WM_QUERYENDSESSION.
  if (base::win::GetVersion() >= base::win::VERSION_VISTA) {
    ChromeBrowserMainPartsWin::RegisterApplicationRestart(
        parsed_command_line());
  }

  // Verify that the profile is not on a network share and if so prepare to show
  // notification to the user.
  if (NetworkProfileBubble::ShouldCheckNetworkProfile(profile_)) {
    content::BrowserThread::PostTask(content::BrowserThread::FILE, FROM_HERE,
        base::Bind(&NetworkProfileBubble::CheckNetworkProfile,
                   profile_->GetPath()));
  }
#endif  // OS_WIN

#if defined(ENABLE_RLZ) && !defined(OS_CHROMEOS)
  // Init the RLZ library. This just binds the dll and schedules a task on the
  // file thread to be run sometime later. If this is the first run we record
  // the installation event.
  PrefService* pref_service = profile_->GetPrefs();
  int ping_delay = do_first_run_tasks_ ? master_prefs_->ping_delay :
      pref_service->GetInteger(first_run::GetPingDelayPrefName().c_str());
  // Negative ping delay means to send ping immediately after a first search is
  // recorded.
  RLZTracker::InitRlzFromProfileDelayed(
      profile_, do_first_run_tasks_, ping_delay < 0,
      base::TimeDelta::FromMilliseconds(abs(ping_delay)));
#endif  // defined(ENABLE_RLZ) && !defined(OS_CHROMEOS)

  // Configure modules that need access to resources.
  net::NetModule::SetResourceProvider(chrome_common_net::NetResourceProvider);

  // In unittest mode, this will do nothing.  In normal mode, this will create
  // the global IntranetRedirectDetector instance, which will promptly go to
  // sleep for seven seconds (to avoid slowing startup), and wake up afterwards
  // to see if it should do anything else.
  //
  // A simpler way of doing all this would be to have some function which could
  // give the time elapsed since startup, and simply have this object check that
  // when asked to initialize itself, but this doesn't seem to exist.
  //
  // This can't be created in the BrowserProcessImpl constructor because it
  // needs to read prefs that get set after that runs.
  browser_process_->intranet_redirect_detector();
  GoogleSearchCounter::RegisterForNotifications();

  // Disable SDCH filtering if switches::kEnableSdch is 0.
  int sdch_enabled = 1;
  if (parsed_command_line().HasSwitch(switches::kEnableSdch)) {
    base::StringToInt(parsed_command_line().GetSwitchValueASCII(
        switches::kEnableSdch), &sdch_enabled);
    if (!sdch_enabled)
      net::SdchManager::EnableSdchSupport(false);
  }
  if (sdch_enabled) {
    // Perform A/B test to measure global impact of SDCH support.
    // Set up a field trial to see what disabling SDCH does to latency of page
    // layout globally.
    base::FieldTrial::Probability kSDCH_DIVISOR = 1000;
    base::FieldTrial::Probability kSDCH_DISABLE_PROBABILITY = 1;  // 0.1% prob.
    // After March 31, 2012 builds, it will always be in default group.
    int sdch_enabled_group = -1;
    scoped_refptr<base::FieldTrial> sdch_trial(
        base::FieldTrialList::FactoryGetFieldTrial(
            "GlobalSdch", kSDCH_DIVISOR, "global_enable_sdch", 2012, 3, 31,
            &sdch_enabled_group));

    sdch_trial->AppendGroup("global_disable_sdch",
                            kSDCH_DISABLE_PROBABILITY);
    if (sdch_enabled_group != sdch_trial->group())
      net::SdchManager::EnableSdchSupport(false);
  }

  if (parsed_command_line().HasSwitch(switches::kEnableWatchdog))
    InstallJankometer(parsed_command_line());

#if defined(OS_WIN) && !defined(GOOGLE_CHROME_BUILD)
  if (parsed_command_line().HasSwitch(switches::kDebugPrint)) {
    base::FilePath path =
        parsed_command_line().GetSwitchValuePath(switches::kDebugPrint);
    printing::PrintedDocument::set_debug_dump_path(path);
  }
#endif

  HandleTestParameters(parsed_command_line());
  RecordBreakpadStatusUMA(browser_process_->metrics_service());
  about_flags::RecordUMAStatistics(local_state_);
#if defined(ENABLE_LANGUAGE_DETECTION)
  LanguageUsageMetrics::RecordAcceptLanguages(
      profile_->GetPrefs()->GetString(prefs::kAcceptLanguages));
  LanguageUsageMetrics::RecordApplicationLanguage(
      browser_process_->GetApplicationLocale());
#endif

  // Querying the default browser state can be slow, do it in the background.
  BrowserThread::GetBlockingPool()->PostDelayedTask(
        FROM_HERE,
        base::Bind(&RecordDefaultBrowserUMAStat),
        base::TimeDelta::FromSeconds(5));

  // The extension service may be available at this point. If the command line
  // specifies --uninstall-extension, attempt the uninstall extension startup
  // action.
  if (parsed_command_line().HasSwitch(switches::kUninstallExtension)) {
    extensions::StartupHelper extension_startup_helper;
    if (extension_startup_helper.UninstallExtension(
            parsed_command_line(), profile_))
      return content::RESULT_CODE_NORMAL_EXIT;
    return chrome::RESULT_CODE_UNINSTALL_EXTENSION_ERROR;
  }

  // Start watching for hangs during startup. We disarm this hang detector when
  // ThreadWatcher takes over or when browser is shutdown or when
  // startup_watcher_ is deleted.
  startup_watcher_->Arm(base::TimeDelta::FromSeconds(300));

  // On mobile, need for clean shutdown arises only when the application comes
  // to foreground (i.e. MetricsService::OnAppEnterForeground is called).
  // http://crbug.com/179143
#if !defined(OS_ANDROID)
  // Start watching for a hang.
  MetricsService::LogNeedForCleanShutdown();
#endif

#if defined(OS_WIN)
  // We check this here because if the profile is OTR (chromeos possibility)
  // it won't still be accessible after browser is destroyed.
  record_search_engine_ = do_first_run_tasks_ && !profile_->IsOffTheRecord();
#endif

  // Create the instance of the cloud print proxy service so that it can launch
  // the service process if needed. This is needed because the service process
  // might have shutdown because an update was available.
  // TODO(torne): this should maybe be done with
  // ProfileKeyedServiceFactory::ServiceIsCreatedWithProfile() instead?
#if !defined(OS_ANDROID)
  CloudPrintProxyServiceFactory::GetForProfile(profile_);
#endif

  // Start watching all browser threads for responsiveness.
  ThreadWatcherList::StartWatchingAll(parsed_command_line());

#if !defined(DISABLE_NACL)
  if (parsed_command_line().HasSwitch(switches::kPnaclDir)) {
    PathService::Override(chrome::DIR_PNACL_BASE,
                          parsed_command_line().GetSwitchValuePath(
                              switches::kPnaclDir));
  }
  NaClProcessHost::EarlyStartup();
#endif

  PreBrowserStart();

  // Instantiate the notification UI manager, as this triggers a perf timer
  // used to measure startup time. TODO(stevenjb): Figure out what is actually
  // triggering the timer and call that explicitly in the approprate place.
  // http://crbug.com/105065.
  browser_process_->notification_ui_manager();

#if !defined(OS_ANDROID)
  // Most general initialization is behind us, but opening a
  // tab and/or session restore and such is still to be done.
  base::TimeTicks browser_open_start = base::TimeTicks::Now();

  // We are in regular browser boot sequence. Open initial tabs and enter the
  // main message loop.
  int result_code;
#if defined(OS_CHROMEOS)
  // On ChromeOS multiple profiles doesn't apply, and will break if we load
  // them this early as the cryptohome hasn't yet been mounted (which happens
  // only once we log in.
  std::vector<Profile*> last_opened_profiles;
#else
  std::vector<Profile*> last_opened_profiles =
      g_browser_process->profile_manager()->GetLastOpenedProfiles();
#endif

  if (!parsed_command_line().HasSwitch(switches::kDisableComponentUpdate))
    RegisterComponentsForUpdate(parsed_command_line());

  if (browser_creator_->Start(parsed_command_line(), base::FilePath(),
                              profile_, last_opened_profiles, &result_code)) {
#if defined(OS_WIN) || (defined(OS_LINUX) && !defined(OS_CHROMEOS))
    // Initialize autoupdate timer. Timer callback costs basically nothing
    // when browser is not in persistent mode, so it's OK to let it ride on
    // the main thread. This needs to be done here because we don't want
    // to start the timer when Chrome is run inside a test harness.
    browser_process_->StartAutoupdateTimer();
#endif

#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
    // On Linux, the running exe will be updated if an upgrade becomes
    // available while the browser is running.  We need to save the last
    // modified time of the exe, so we can compare to determine if there is
    // an upgrade while the browser is kept alive by a persistent extension.
    upgrade_util::SaveLastModifiedTimeOfExe();
#endif

    // Record now as the last successful chrome start.
    GoogleUpdateSettings::SetLastRunTime();

#if defined(OS_MACOSX)
    // Call Recycle() here as late as possible, before going into the loop
    // because Start() will add things to it while creating the main window.
    if (parameters().autorelease_pool)
      parameters().autorelease_pool->Recycle();
#endif

    RecordPreReadExperimentTime("Startup.BrowserOpenTabs",
                                base::TimeTicks::Now() - browser_open_start);

    // If we're running tests (ui_task is non-null), then we don't want to
    // call FetchLanguageListFromTranslateServer or
    // StartRepeatedVariationsSeedFetch.
    if (parameters().ui_task == NULL) {
      // Request new variations seed information from server.
      chrome_variations::VariationsService* variations_service =
          browser_process_->variations_service();
      if (variations_service) {
        variations_service->StartRepeatedVariationsSeedFetch();

#if defined(OS_WIN)
        variations_service->StartGoogleUpdateRegistrySync();
#endif
      }

#if !defined(OS_CHROMEOS)
      // TODO(mad): Move this call in a proper place on CrOS.
      // http://crosbug.com/17687
      if (translate_manager_ != NULL) {
        translate_manager_->FetchLanguageListFromTranslateServer(
            profile_->GetPrefs());
      }
#endif
    }

    run_message_loop_ = true;
  } else {
    run_message_loop_ = false;
  }
  browser_creator_.reset();
#endif  // !defined(OS_ANDROID)

  RecordTouchEventState(parsed_command_line());

  PostBrowserStart();

  if (parameters().ui_task) {
    // We end the startup timer here if we have parameters to run, because we
    // never start to run the main loop (where we normally stop the timer).
    startup_timer_->SignalStartupComplete(
        performance_monitor::StartupTimer::STARTUP_TEST);
    parameters().ui_task->Run();
    delete parameters().ui_task;
    run_message_loop_ = false;
  }

  return result_code_;
}

bool ChromeBrowserMainParts::MainMessageLoopRun(int* result_code) {
#if defined(OS_ANDROID)
  // Chrome on Android does not use default MessageLoop. It has its own
  // Android specific MessageLoop
  NOTREACHED();
  return true;
#else
  // Set the result code set in PreMainMessageLoopRun or set above.
  *result_code = result_code_;
  if (!run_message_loop_)
    return true;  // Don't run the default message loop.

  // These should be invoked as close to the start of the browser's
  // UI thread message loop as possible to get a stable measurement
  // across versions.
  RecordBrowserStartupTime();
  startup_timer_->SignalStartupComplete(
      performance_monitor::StartupTimer::STARTUP_NORMAL);

  DCHECK_EQ(MessageLoop::TYPE_UI, MessageLoop::current()->type());
#if !defined(USE_AURA) && defined(TOOLKIT_VIEWS)
  views::AcceleratorHandler accelerator_handler;
  base::RunLoop run_loop(&accelerator_handler);
#else
  base::RunLoop run_loop;
#endif

  if (CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kPerformanceMonitorGathering)) {
    performance_monitor::PerformanceMonitor::GetInstance()->Start();
  }

  run_loop.Run();

  return true;
#endif
}

void ChromeBrowserMainParts::PostMainMessageLoopRun() {
#if defined(OS_ANDROID)
  // Chrome on Android does not use default MessageLoop. It has its own
  // Android specific MessageLoop
  NOTREACHED();
#else

#if defined(USE_X11)
  // Unset the X11 error handlers. The X11 error handlers log the errors using a
  // |PostTask()| on the message-loop. But since the message-loop is in the
  // process of terminating, this can cause errors.
  UnsetBrowserX11ErrorHandlers();
#endif

  // Start watching for jank during shutdown. It gets disarmed when
  // |shutdown_watcher_| object is destructed.
  shutdown_watcher_->Arm(base::TimeDelta::FromSeconds(300));

  // Disarm the startup hang detector time bomb if it is still Arm'ed.
  startup_watcher_->Disarm();

  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
    chrome_extra_parts_[i]->PostMainMessageLoopRun();

#if !defined(OS_ANDROID)
  gpu_util::UninstallBrowserMonitor();
#endif

#if defined(OS_WIN)
  // Log the search engine chosen on first run. Do this at shutdown, after any
  // changes are made from the first run bubble link, etc.
  if (record_search_engine_) {
    TemplateURLService* url_service =
        TemplateURLServiceFactory::GetForProfile(profile_);
    const TemplateURL* default_search_engine =
        url_service->GetDefaultSearchProvider();
    // The default engine can be NULL if the administrator has disabled
    // default search.
    SearchEngineType search_engine_type =
        TemplateURLPrepopulateData::GetEngineType(default_search_engine ?
            default_search_engine->url() : std::string());
    // Record the search engine chosen.
    UMA_HISTOGRAM_ENUMERATION("Chrome.SearchSelectExempt", search_engine_type,
                              SEARCH_ENGINE_MAX);
  }
#endif

  // Some tests don't set parameters.ui_task, so they started translate
  // language fetch that was never completed so we need to cleanup here
  // otherwise it will be done by the destructor in a wrong thread.
  if (parameters().ui_task == NULL && translate_manager_ != NULL)
    translate_manager_->CleanupPendingUlrFetcher();

  if (notify_result_ == ProcessSingleton::PROCESS_NONE)
    process_singleton_->Cleanup();

  // Stop all tasks that might run on WatchDogThread.
  ThreadWatcherList::StopWatchingAll();

  browser_process_->metrics_service()->Stop();

  restart_last_session_ = browser_shutdown::ShutdownPreThreadsStop();
  browser_process_->StartTearDown();
#endif
}

void ChromeBrowserMainParts::PostDestroyThreads() {
#if defined(OS_ANDROID)
  // On Android, there is no quit/exit. So the browser's main message loop will
  // not finish.
  NOTREACHED();
#else
  browser_process_->PostDestroyThreads();
  // browser_shutdown takes care of deleting browser_process, so we need to
  // release it.
  ignore_result(browser_process_.release());
  browser_shutdown::ShutdownPostThreadsStop(restart_last_session_);
  master_prefs_.reset();
  process_singleton_.reset();

  // We need to do this check as late as possible, but due to modularity, this
  // may be the last point in Chrome.  This would be more effective if done at
  // a higher level on the stack, so that it is impossible for an early return
  // to bypass this code.  Perhaps we need a *final* hook that is called on all
  // paths from content/browser/browser_main.
  CHECK(MetricsService::UmaMetricsProperlyShutdown());
#endif
}

// Public members:

void ChromeBrowserMainParts::AddParts(ChromeBrowserMainExtraParts* parts) {
  chrome_extra_parts_.push_back(parts);
}

// Misc ------------------------------------------------------------------------

void RecordBrowserStartupTime() {
  // Don't record any metrics if UI was displayed before this point e.g.
  // warning dialogs.
  if (startup_metric_utils::WasNonBrowserUIDisplayed())
    return;

// CurrentProcessInfo::CreationTime() is currently only implemented on Mac and
// Windows.
#if defined(OS_MACOSX) || defined(OS_WIN)
  const base::Time *process_creation_time =
      base::CurrentProcessInfo::CreationTime();

  if (process_creation_time)
    RecordPreReadExperimentTime("Startup.BrowserMessageLoopStartTime",
        base::Time::Now() - *process_creation_time);
#endif // OS_MACOSX || OS_WIN

  // Record collected startup metrics.
  startup_metric_utils::OnBrowserStartupComplete();

  // Deletes self.
  new LoadCompleteListener();
}

// This code is specific to the Windows-only PreReadExperiment field-trial.
void RecordPreReadExperimentTime(const char* name, base::TimeDelta time) {
  DCHECK(name != NULL);

  // This gets called with different histogram names, so we don't want to use
  // the UMA_HISTOGRAM_CUSTOM_TIMES macro--it uses a static variable, and the
  // first call wins.
  AddPreReadHistogramTime(name, time);

#if defined(OS_WIN)
#if defined(GOOGLE_CHROME_BUILD)
  // The pre-read experiment is Windows and Google Chrome specific.
  scoped_ptr<base::Environment> env(base::Environment::Create());

  // Only record the sub-histogram result if the experiment is running
  // (environment variable is set, and valid).
  std::string pre_read_percentage;
  if (env->GetVar(chrome::kPreReadEnvironmentVariable, &pre_read_percentage)) {
    std::string uma_name(name);

    // We want XP to record a separate histogram, as the loader on XP
    // is very different from the Vista and Win7 loaders.
    if (base::win::GetVersion() <= base::win::VERSION_XP)
      uma_name += "_XP";

    uma_name += "_PreRead_";
    uma_name += pre_read_percentage;
    AddPreReadHistogramTime(uma_name.c_str(), time);
  }
#endif
#endif
}