[Android] Add enhanced bookmark opt-in flag.

chrome/browser/about_flags.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/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 1988 matching lines @@
 
 void GetSanitizedEnabledFlags(
     FlagsStorage* flags_storage, std::set<std::string>* result) {
   SanitizeList(flags_storage);
   *result = flags_storage->GetFlags();
 }
 
 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.
     if (command_line->HasSwitch(switches::kEnhancedBookmarksExperiment))
       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"))) {
     return true;
   }
 
 #if defined(OS_ANDROID)
   // enable-data-reduction-proxy-dev is only available for the Dev channel.
   if (!strcmp("enable-data-reduction-proxy-dev", experiment.internal_name) &&
       chrome::VersionInfo::GetChannel() != chrome::VersionInfo::CHANNEL_DEV) {
@@ skipping 446 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags