Subframes in inner WebContents should not create proxies in process of outer WebContents.

content/browser/frame_host/cross_process_frame_connector.cc

 // 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 "content/browser/frame_host/cross_process_frame_connector.h"
 
 #include "cc/surfaces/surface.h"
 #include "cc/surfaces/surface_manager.h"
 #include "content/browser/compositor/surface_utils.h"
 #include "content/browser/frame_host/frame_tree_node.h"
@@ skipping 134 matching lines @@
   return child_frame_rect_;
 }
 
 void CrossProcessFrameConnector::GetScreenInfo(blink::WebScreenInfo* results) {
   // Inner WebContents's root FrameTreeNode does not have a parent(), so
   // GetRenderWidgetHostView() call below will fail.
   // TODO(lazyboy): Fix this.
   if (frame_proxy_in_parent_renderer_->frame_tree_node()
           ->render_manager()
           ->ForInnerDelegate()) {
+    DCHECK(frame_proxy_in_parent_renderer_->frame_tree_node()->IsMainFrame());
     return;
   }
 
   RenderWidgetHostView* rwhv =
       frame_proxy_in_parent_renderer_->GetRenderWidgetHostView();
   if (rwhv)
     static_cast<RenderWidgetHostViewBase*>(rwhv)->GetScreenInfo(results);
 }
 
 void CrossProcessFrameConnector::OnForwardInputEvent(
@@ skipping 42 matching lines @@
   }
 }
 
 void CrossProcessFrameConnector::SetSize(gfx::Rect frame_rect) {
   child_frame_rect_ = frame_rect;
   if (view_)
     view_->SetSize(frame_rect.size());
 }
 
 }  // namespace content