Add support for temporarily disabling sync.

chrome/browser/sync/sync_prefs.h

 // Copyright (c) 2011 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_SYNC_SYNC_PREFS_H_
 #define CHROME_BROWSER_SYNC_SYNC_PREFS_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
@@ skipping 51 matching lines @@
   void ClearPreferences();
 
   // Getters and setters for global sync prefs.
 
   bool HasSyncSetupCompleted() const;
   void SetSyncSetupCompleted();
 
   bool IsStartSuppressed() const;
   void SetStartSuppressed(bool is_suppressed);
 
+  std::string GetGoogleServicesUsername() const;
+
   base::Time GetLastSyncedTime() const;
   void SetLastSyncedTime(base::Time time);
 
   bool HasKeepEverythingSynced() const;
   void SetKeepEverythingSynced(bool keep_everything_synced);
 
   // The returned set is guaranteed to be a subset of
   // |registered_types|.  Returns |registered_types| directly if
   // HasKeepEverythingSynced() is true.
   syncable::ModelTypeSet GetPreferredDataTypes(
@@ skipping 51 matching lines @@
   // The preference that controls whether sync is under control by
   // configuration management.
   BooleanPrefMember pref_sync_managed_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncPrefs);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_SYNC_PREFS_H_