Changed Finch experiment opt-in code. Adding command flag didn't work because Finch reads them only early at start-up time. So had to add hidden about flag experiments to make command flag persistent.

finnur:
  chrome\browser\extensions\external_component_loader.cc
brettw:
  chrome\browser\bookmarks\enhanced_bookmarks_features.cc
  chrome\browser\bookmarks\enhanced_bookmarks_features.h
zea:
  chrome\browser\sync\profile_sync_service.cc

BUG=321393

Review URL: https://codereview.chromium.org/192443005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@257213 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 78e0859..2c6b779 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -1730,6 +1730,20 @@
         switches::kEnhancedBookmarksExperiment, "1",
         switches::kEnhancedBookmarksExperiment, "0")
   },
+  {
+    "manual-enhanced-bookmarks",
+    IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_NAME,
+    IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_DESCRIPTION,
+    kOsDesktop,
+    SINGLE_VALUE_TYPE(switches::kManualEnhancedBookmarks)
+  },
+  {
+    "manual-enhanced-bookmarks-optout",
+    IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_NAME,
+    IDS_FLAGS_ENABLE_ENHANCED_BOOKMARKS_DESCRIPTION,
+    kOsDesktop,
+    SINGLE_VALUE_TYPE(switches::kManualEnhancedBookmarksOptout)
+  },
 #if defined(OS_ANDROID)
   {
     "enable-zero-suggest-experiment",
@@ -1963,6 +1977,11 @@
 
     return !IsEnhancedBookmarksExperimentEnabled();
   }
+  if ((experiment.internal_name == std::string("manual-enhanced-bookmarks")) ||
+      (experiment.internal_name ==
+           std::string("manual-enhanced-bookmarks-optout"))) {
+    return true;
+  }
 
   return false;
 }