Add onChanged events to the extension settings API, both from sync and between

chrome/browser/extensions/extension_settings_storage_unittest.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_UNITTEST_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_SETTINGS_STORAGE_UNITTEST_H_
 #pragma once
 
 #include "testing/gtest/include/gtest/gtest.h"
 
+#include "base/bind.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/scoped_temp_dir.h"
 #include "base/task.h"
 #include "chrome/browser/extensions/extension_settings_backend.h"
+#include "chrome/browser/extensions/extension_settings_frontend.h"
+#include "chrome/test/base/testing_profile.h"
 #include "content/browser/browser_thread.h"
 
 // Parameter type for the value-parameterized tests.
 typedef ExtensionSettingsStorage* (*ExtensionSettingsStorageTestParam)(
     const FilePath& file_path, const std::string& extension_id);
 
 // Test fixture for ExtensionSettingsStorage tests.  Tests are defined in
 // extension_settings_storage_unittest.cc with configurations for both cached
 // and non-cached leveldb storage, and cached no-op storage.
 class ExtensionSettingsStorageTest
@@ skipping 27 matching lines @@
   std::set<std::string> empty_set_;
   std::set<std::string> set1_;
   std::set<std::string> set2_;
   std::set<std::string> set3_;
   std::set<std::string> set12_;
   std::set<std::string> set13_;
   std::set<std::string> set123_;
 
   scoped_ptr<DictionaryValue> empty_dict_;
   scoped_ptr<DictionaryValue> dict1_;
+  scoped_ptr<DictionaryValue> dict3_;
   scoped_ptr<DictionaryValue> dict12_;
   scoped_ptr<DictionaryValue> dict123_;
 
  private:
   ScopedTempDir temp_dir_;
 
   // Need these so that the DCHECKs for running on FILE or UI threads pass.
   MessageLoop message_loop_;
   BrowserThread ui_thread_;
   BrowserThread file_thread_;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SETTINGS_STORAGE_UNITTEST_H_