Hook up guest browser plugins to the accessibility tree.

content/browser/frame_host/render_frame_host_delegate.cc

 // 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.
 
 #include <stddef.h>
 
 #include "base/callback.h"
 #include "base/strings/string16.h"
 #include "content/browser/frame_host/render_frame_host_delegate.h"
 #include "ui/gfx/native_widget_types.h"
@@ skipping 30 matching lines @@
     const MediaResponseCallback& callback) {
   callback.Run(MediaStreamDevices(),
                MEDIA_DEVICE_INVALID_STATE,
                scoped_ptr<MediaStreamUI>());
 }
 
 AccessibilityMode RenderFrameHostDelegate::GetAccessibilityMode() const {
   return AccessibilityModeOff;
 }
 
+RenderFrameHost* RenderFrameHostDelegate::GetGuestByInstanceID(
+    int browser_plugin_instance_id) {
+  return NULL;
+}
+
 #if defined(OS_WIN)
 gfx::NativeViewAccessible
     RenderFrameHostDelegate::GetParentNativeViewAccessible() {
   return NULL;
 }
 #endif  // defined(OS_WIN)
 
 }  // namespace content