Revert 110685 - Fix Clang error on SettingChange.

chrome/browser/protector/setting_change.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_PROTECTOR_SETTING_CHANGE_H_
 #define CHROME_BROWSER_PROTECTOR_SETTING_CHANGE_H_
 #pragma once
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/string16.h"
 
 class TemplateURL;
 
 namespace protector {
 
 class Protector;
 
 // Base class for setting change tracked by Protector.
 class SettingChange {
  public:
-  SettingChange();
-  virtual ~SettingChange();
+  SettingChange() {}
+  virtual ~SettingChange() {}
 
   // Applies initial actions to the setting if needed. Must be called before
   // any other calls are made, including text getters. Returns true if
   // initialization was successful.
-  virtual bool Init(Protector* protector);
+  virtual bool Init(Protector* protector) { return true; }
 
   // Persists new setting if needed.
-  virtual void Apply(Protector* protector);
+  virtual void Apply(Protector* protector) {}
 
   // Restores old setting if needed.
-  virtual void Discard(Protector* protector);
+  virtual void Discard(Protector* protector) {}
 
   // Returns the wrench menu item and bubble title.
   virtual string16 GetTitle() const = 0;
 
   // Returns the bubble message text.
   virtual string16 GetMessage() const = 0;
 
   // Returns text for the button to apply the change with |Apply|.
   // Returns empty string if no apply button should be shown.
   virtual string16 GetApplyButtonText() const = 0;
@@ skipping 11 matching lines @@
 // Allocates and initializes SettingChange implementation for default search
 // provider setting. Both |actual| and |backup| may be NULL if corresponding
 // values are unknown or invalid.
 SettingChange* CreateDefaultSearchProviderChange(
     const TemplateURL* actual,
     const TemplateURL* backup);
 
 }  // namespace protector
 
 #endif  // CHROME_BROWSER_PROTECTOR_SETTING_CHANGE_H_