Add OVERRIDE to webkit/.

webkit/tools/test_shell/test_shell_webmimeregistry_impl.h

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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 WEBKIT_TOOLS_TEST_SHELL_TEST_SHELL_WEBMIMEREGISTRY_IMPL_H_
 #define WEBKIT_TOOLS_TEST_SHELL_TEST_SHELL_WEBMIMEREGISTRY_IMPL_H_
 
 #include <string>
 #include <vector>
 
+#include "base/compiler_specific.h"
 #include "base/hash_tables.h"
 #include "webkit/glue/simple_webmimeregistry_impl.h"
 
 class TestShellWebMimeRegistryImpl
     : public webkit_glue::SimpleWebMimeRegistryImpl {
  public:
   TestShellWebMimeRegistryImpl();
   virtual ~TestShellWebMimeRegistryImpl();
 
   // Override to force that we only support ogg, vorbis and theora.
   //
   // Media layout tests use canPlayType() to determine the test input files.
   // Different flavours of Chromium support different codecs, which has an
   // impact on how canPlayType() behaves.  Since Chromium's baselines are
   // generated against ogg/vorbis/theora content we need to lock down how
   // canPlayType() behaves when running layout tests.
   virtual WebKit::WebMimeRegistry::SupportsType supportsMediaMIMEType(
-      const WebKit::WebString&, const WebKit::WebString&);
+      const WebKit::WebString&, const WebKit::WebString&) OVERRIDE;
 
  private:
   bool IsSupportedMediaMimeType(const std::string& mime_type);
   bool AreSupportedMediaCodecs(const std::vector<std::string>& codecs);
 
   typedef base::hash_set<std::string> MimeMappings;
   MimeMappings media_map_;
   MimeMappings codecs_map_;
 
   DISALLOW_COPY_AND_ASSIGN(TestShellWebMimeRegistryImpl);
 };
 
 #endif  // WEBKIT_TOOLS_TEST_SHELL_TEST_SHELL_WEBMIMEREGISTRY_IMPL_H_