Consolidated enhanced bookmarks experiment logic in one place.

chrome/browser/bookmarks/enhanced_bookmarks_features.h

 // Copyright 2013 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.
 
 #ifndef CHROME_BROWSER_BOOKMARKS_ENHANCED_BOOKMARKS_FEATURES_H_
 #define CHROME_BROWSER_BOOKMARKS_ENHANCED_BOOKMARKS_FEATURES_H_
 
 #include <string>
 
 #include "extensions/common/extension.h"
 
 class PrefService;
 
 // States for bookmark experiment. They are set by Chrome sync into
 // sync_driver::prefs::kEnhancedBookmarksExperimentEnabled user preference and
 // used for UMA reporting as well.
 enum BookmarksExperimentState {
   kNoBookmarksExperiment,

[sky, 2014/05/23 19:51:56]

This is the wrong style for enums in chrome, they should be ALL_CAPS. Please do
a follow on patch that fixes this.

   kBookmarksExperimentEnabled,
   kBookmarksExperimentEnabledUserOptOut,
   kBookmarksExperimentEnabledFromFinch,
   kBookmarksExperimentOptOutFromFinch,
   kBookmarksExperimentEnabledFromFinchUserSignedIn,
+  kBookmarksExperimentEnabledFromSyncUnknown,
   kBookmarksExperimentEnumSize
 };
 
 // Returns true and sets |extension_id| if bookmarks experiment enabled
 //         false if no bookmark experiment or extension id is empty.
 bool GetBookmarksExperimentExtensionID(const PrefService* user_prefs,
                                        std::string* extension_id);
 
 // Updates bookmark experiment state based on information from Chrome sync
 // and Finch experiments.
-void UpdateBookmarksExperimentState(PrefService* user_prefs,
-                                    PrefService* local_state,
-                                    bool user_signed_in);
+void UpdateBookmarksExperimentState(
+    PrefService* user_prefs,
+    PrefService* local_state,
+    bool user_signed_in,
+    BookmarksExperimentState experiment_enabled_from_sync);
 
 // Sets flag to opt-in user into Finch experiment.
 void ForceFinchBookmarkExperimentIfNeeded(
     PrefService* local_state,
     BookmarksExperimentState bookmarks_experiment_state);
 
 // Returns true if enhanced bookmarks experiment is enabled.
 // Experiment could be enable from Chrome sync or from Finch.
 bool IsEnhancedBookmarksExperimentEnabled();
 
 // Returns true when flag enable-dom-distiller is set or enabled from Finch.
 bool IsEnableDomDistillerSet();
 
 // Returns true when flag enable-sync-articles is set or enabled from Finch.
 bool IsEnableSyncArticlesSet();
 
 #endif  // CHROME_BROWSER_BOOKMARKS_ENHANCED_BOOKMARKS_FEATURES_H_