Update WebFrameTestProxy and WebTestProxy to mostly follow Chrome style.

content/shell/renderer/test_runner/MockWebMIDIAccessor.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_MOCKWEBMIDIACCESSOR_H_
 #define CONTENT_SHELL_RENDERER_TEST_RUNNER_MOCKWEBMIDIACCESSOR_H_
 
 #include "base/basictypes.h"
 #include "content/shell/renderer/test_runner/TestCommon.h"
 #include "content/shell/renderer/test_runner/WebTask.h"
@@ skipping 13 matching lines @@
     virtual ~MockWebMIDIAccessor();
 
     // blink::WebMIDIAccessor implementation.
     virtual void startSession() OVERRIDE;
     virtual void sendMIDIData(unsigned portIndex,
                               const unsigned char* data,
                               size_t length,
                               double timestamp) OVERRIDE {}
 
     // WebTask related methods
-    WebTaskList* taskList() { return &m_taskList; }
+    WebTaskList* mutable_task_list() { return &m_taskList; }
 
 private:
     blink::WebMIDIAccessorClient* m_client;
     WebTaskList m_taskList;
     TestInterfaces* m_interfaces;
 
     DISALLOW_COPY_AND_ASSIGN(MockWebMIDIAccessor);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_SHELL_RENDERER_TEST_RUNNER_MOCKWEBMIDIACCESSOR_H_