Revert 176015

chrome/browser/extensions/api/storage/settings_observer.h

Index: chrome/browser/extensions/api/storage/settings_observer.h
===================================================================
--- chrome/browser/extensions/api/storage/settings_observer.h	(revision 176046)
+++ chrome/browser/extensions/api/storage/settings_observer.h	(working copy)
@@ -1,30 +0,0 @@
-// 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_API_STORAGE_SETTINGS_OBSERVER_H_
-#define CHROME_BROWSER_EXTENSIONS_API_STORAGE_SETTINGS_OBSERVER_H_
-
-#include "base/observer_list_threadsafe.h"
-#include "chrome/browser/extensions/api/storage/settings_namespace.h"
-
-namespace extensions {
-
-// Interface for classes that listen to changes to extension settings.
-class SettingsObserver {
- public:
-  // Called when a list of settings have changed for an extension.
-  virtual void OnSettingsChanged(
-      const std::string& extension_id,
-      settings_namespace::Namespace settings_namespace,
-      const std::string& changes_json) = 0;
-
-  virtual ~SettingsObserver() {}
-};
-
-typedef ObserverListThreadSafe<SettingsObserver>
-    SettingsObserverList;
-
-}  // namespace extensions
-
-#endif  // CHROME_BROWSER_EXTENSIONS_API_STORAGE_SETTINGS_OBSERVER_H_