[Sync] Add support for automatic enabling of syncing tab favicons.

sync/util/sync_experiments.h

+// 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.
+
+#ifndef SYNC_UTIL_SYNC_EXPERIMENTS_
+#define SYNC_UTIL_SYNC_EXPERIMENTS_
+#pragma once
+
+#include "sync/syncable/model_type.h"
+
+namespace browser_sync {
+
+// A structure to hold the enable status of experimental sync features.
+struct SyncExperiments {

[tim (not reviewing), 2012/04/26 22:25:32]

Since this is already in browser_sync, I think just Experiments is sufficient. 

[Nicolas Zea, 2012/04/26 22:50:30]

Done.

+  SyncExperiments() : sync_tabs(false), sync_tab_favicons(false) {}
+
+  bool Matches(const SyncExperiments& rhs) {
+    return (sync_tabs == rhs.sync_tabs) &&
+           (sync_tab_favicons == rhs.sync_tab_favicons);
+  }
+
+  // Enable the tab sync (SESSIONS) datatype.
+  bool sync_tabs;
+
+  // Enable syncing of favicons within tab sync (only has an effect if tab sync
+  // is already enabled). This takes effect on the next restart.
+  bool sync_tab_favicons;
+};
+
+}
+
+#endif  // SYNC_UTIL_SYNC_EXPERIMENTS_