Revert of Cross-process iframe accessibility.

content/renderer/accessibility/renderer_accessibility.cc

 // 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.
 
 #include "content/renderer/accessibility/renderer_accessibility.h"
 
 #include "content/renderer/render_frame_impl.h"
 #include "content/renderer/render_view_impl.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebFrame.h"
 #include "third_party/WebKit/public/web/WebView.h"
 
 using blink::WebDocument;
 using blink::WebFrame;
 using blink::WebView;
 
 namespace content {
 
 RendererAccessibility::RendererAccessibility(
     RenderFrameImpl* render_frame)
     : RenderFrameObserver(render_frame),
       render_frame_(render_frame) {
 }
 
 RendererAccessibility::~RendererAccessibility() {
 }
 
 WebDocument RendererAccessibility::GetMainDocument() {
-  if (render_frame_ && render_frame_->GetWebFrame())
-    return render_frame_->GetWebFrame()->document();
+  WebView* view = render_frame_->render_view()->GetWebView();
+  WebFrame* main_frame = view ? view->mainFrame() : NULL;
+
+  if (main_frame)
+    return main_frame->document();
+
   return WebDocument();
 }
 
 }  // namespace content