Enable sync for the settings from the Extension Settings API.

chrome/browser/extensions/extension_settings_storage.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_EXTENSIONS_EXTENSION_SETTINGS_STORAGE_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_SETTINGS_STORAGE_H_
 #pragma once
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 17 matching lines @@
   // Supports lightweight copying.
   class Result {
    public:
     // Ownership of settings taken.
     explicit Result(DictionaryValue* settings);
     explicit Result(const std::string& error);
     ~Result();
 
     // The dictionary result of the computation.  NULL does not imply invalid;
     // HasError() should be used to test this.
-    // Wwnership remains with with the Result.
+    // Ownership remains with with the Result.
     DictionaryValue* GetSettings() const;
 
     // Whether there was an error in the computation.  If so, the results of
     // GetSettings and ReleaseSettings are not valid.
     bool HasError() const;
 
     // Gets the error message, if any.
     const std::string& GetError() const;
 
    private:
@@ skipping 38 matching lines @@
   // Removes multiple keys from the storage.
   // If successful, result value is NULL.
   virtual Result Remove(const std::vector<std::string>& keys) = 0;
 
   // Clears the storage.
   // If successful, result value is NULL.
   virtual Result Clear() = 0;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SETTINGS_STORAGE_H_