Update all the client code to use a single WebThemeEngine.h header.

content/shell/renderer/test_runner/WebTestThemeEngineMock.h

 // Copyright 2013 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 CONTENT_SHELL_RENDERER_TEST_RUNNER_WEBTESTTHEMEENGINEMOCK_H_
 #define CONTENT_SHELL_RENDERER_TEST_RUNNER_WEBTESTTHEMEENGINEMOCK_H_
 
 #include "third_party/WebKit/public/platform/WebRect.h"
-#include "third_party/WebKit/public/platform/default/WebThemeEngine.h"
+#include "third_party/WebKit/public/platform/WebThemeEngine.h"
 
 using blink::WebRect;
 using blink::WebThemeEngine;
 
 namespace WebTestRunner {
 
 class WebTestThemeEngineMock : public blink::WebThemeEngine {
 public:
     virtual ~WebTestThemeEngineMock() { }
 
     // WebThemeEngine methods:
     virtual blink::WebSize getSize(WebThemeEngine::Part);
 
     virtual void paint(blink::WebCanvas*,
         WebThemeEngine::Part,
         WebThemeEngine::State,
         const blink::WebRect&,
         const WebThemeEngine::ExtraParams*);
 };
 
 } // namespace WebTestRunner
 
 #endif  // CONTENT_SHELL_RENDERER_TEST_RUNNER_WEBTESTTHEMEENGINEMOCK_H_