Split WebLocalFrame into a distinct subclass of WebFrame.

Source/web/tests/WebHelperPluginTest.cpp

 // Copyright 2014 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.
 
 #include "config.h"
 #include "WebHelperPlugin.h"
 
 #include "FakeWebPlugin.h"
 #include "FrameTestHelpers.h"
 #include "WebFrameClient.h"
+#include "WebLocalFrame.h"
 #include <gtest/gtest.h>
 
 namespace blink {
 
 namespace {
 
 class FakePlaceholderWebPlugin : public FakeWebPlugin {
 public:
     FakePlaceholderWebPlugin(blink::WebFrame* frame, const blink::WebPluginParams& params)
         : FakeWebPlugin(frame, params)
@@ skipping 64 matching lines @@
 {
     m_frameClient.setCreatePlaceholder(true);
 
     m_plugin = adoptPtr(WebHelperPlugin::create("hello", m_helper.webView()->mainFrame()->toWebLocalFrame()));
     EXPECT_EQ(0, m_plugin.get());
 }
 
 } // namespace
 
 } // namespace