[content shell] Use the TestRunner library again and remove the mock testRunner

content/shell/webkit_test_runner_bindings.h

-// Copyright (c) 2012 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_WEBKIT_TEST_RUNNER_BINDINGS_H_
-#define CONTENT_SHELL_WEBKIT_TEST_RUNNER_BINDINGS_H_
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "v8/include/v8.h"
-
-namespace content {
-
-class WebKitTestRunnerBindings : public v8::Extension {
- public:
-  WebKitTestRunnerBindings();
-  virtual ~WebKitTestRunnerBindings();
-
-  // v8::Extension implementation.
-  virtual v8::Handle<v8::FunctionTemplate>
-      GetNativeFunction(v8::Handle<v8::String> name) OVERRIDE;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(WebKitTestRunnerBindings);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_SHELL_WEBKIT_TEST_RUNNER_BINDINGS_H_