Add OVERRIDE to chrome/browser/extensions/.

chrome/browser/extensions/extension_clipboard_api.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_CLIPBOARD_API_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_CLIPBOARD_API_H_
 #pragma once
 
 #include "chrome/browser/extensions/extension_function.h"
 
 // Writes data to the clipboard. Data format and buffer data will be written to
 // are specified by parameters passed from the extension.
 // Currently, only writing to standard buffer is possible.
 class WriteDataClipboardFunction : public SyncExtensionFunction {
  public:
-  virtual bool RunImpl();
+  virtual bool RunImpl() OVERRIDE;
 
  private:
   // Writes plain text to the buffer. Ignores url argument if sent from the
   // extension. Only standard buffer is currently supported.
   bool WritePlainText(const std::string& buffer);
   // Writes html to the buffer. Only standard buffer is currently supported.
   bool WriteHtml(const std::string& buffer);
 
   DECLARE_EXTENSION_FUNCTION_NAME("experimental.clipboard.writeData")
 };
 
 // Reads data from the clipboard. Data format and buffer data will be written to
 // are specified by parameters passed from the extension.
 class ReadDataClipboardFunction : public SyncExtensionFunction {
  public:
-  virtual bool RunImpl();
+  virtual bool RunImpl() OVERRIDE;
 
  private:
   // Reads plain text from the clipboard buffer. Callback will have only data
   // property set. Selection buffer not supported for Win and Mac.
   bool ReadPlainText(const std::string& buffer);
   // Reads html from the buffer. Selection buffer not supported for Win and Mac.
   bool ReadHtml(const std::string& buffer);
 
   DECLARE_EXTENSION_FUNCTION_NAME("experimental.clipboard.readData")
 };
 
 // For a given clipbord buffer, returns list of data types available on it.
 class GetAvailableMimeTypesClipboardFunction : public SyncExtensionFunction {
  public:
-  virtual bool RunImpl();
+  virtual bool RunImpl() OVERRIDE;
  private:
   DECLARE_EXTENSION_FUNCTION_NAME("experimental.clipboard.getAvailableTypes")
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_CLIPBOARD_API_H_