Revert of [Android] Disable 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 8e228418ee2bc796b4bd94e22fecbba331746be4..b09be9b2a303b43c5fa8a8321596dc30d430ae75 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -2034,6 +2034,10 @@
                                FlagsStorage* flags_storage) {
   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.
@@ -2041,6 +2045,7 @@
       return false;
 
     return !IsEnhancedBookmarksExperimentEnabled(flags_storage);
+#endif
   }
 
   if ((experiment.internal_name == std::string("manual-enhanced-bookmarks")) ||