Add a UMA stat to track whether Chrome is the default browser.

Also alter the default browser enum in ShellIntegration to be compatible with UMA, and shorten needlessly-long enum value names.

BUG=164653
TEST=NONE


Review URL: https://chromiumcodereview.appspot.com/11472007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@172346 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/process_singleton_win.cc b/chrome/browser/process_singleton_win.cc
index a4694ee..d8073c1 100644
--- a/chrome/browser/process_singleton_win.cc
+++ b/chrome/browser/process_singleton_win.cc
@@ -230,7 +230,7 @@
   if (base::win::IsProcessImmersive(base::GetCurrentProcessHandle()))
     return false;
 
-  if (!ShellIntegration::IsDefaultBrowser())
+  if (ShellIntegration::GetDefaultBrowser() != ShellIntegration::IS_DEFAULT)
     return false;
 
   base::IntegrityLevel integrity_level = base::INTEGRITY_UNKNOWN;