[Android] Add enhanced bookmark opt-in flag.

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 09f8bcc4cef0d00f50b3e9cf0424ed6250b4311e..5582c096c02605bc2fd8231d06fd2661a2989cb1 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -2006,6 +2006,10 @@ void GetSanitizedEnabledFlags(
 bool SkipConditionalExperiment(const Experiment& experiment) {
   if (experiment.internal_name ==
       std::string("enhanced-bookmarks-experiment")) {
+#if defined(OS_ANDROID)
+      // On Android, user can opt in.
+      return false;
+#else
     CommandLine* command_line = CommandLine::ForCurrentProcess();
     // Dont't skip experiment if it has non default value.
     // It means user selected it.
@@ -2013,7 +2017,9 @@ bool SkipConditionalExperiment(const Experiment& experiment) {
       return false;
 
     return !IsEnhancedBookmarksExperimentEnabled();

[Nico, 2014/09/04 18:35:25]

Why is this code needed?

[Kibeom Kim (inactive), 2014/09/04 18:40:49]

For desktop, we enable the experiment by chrome sync or finch (which is turned
on by default in that case), and only they can enable the feature or opt-out. So
there is no reason to show the flag to the non-experiment group.

[Nico, 2014/09/04 18:42:28]

The way this is  usually done is to have a "Enable", "Disable", "Default"
picker, with Default delegating to finch and Enable and Disable enabling and
disabling. Why can't that work here?

+#endif
   }
+
   if ((experiment.internal_name == std::string("manual-enhanced-bookmarks")) ||
       (experiment.internal_name ==
            std::string("manual-enhanced-bookmarks-optout"))) {