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

content/browser/frame_host/render_frame_host_manager.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 "content/browser/frame_host/render_frame_host_manager.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/command_line.h"
@@ skipping 245 matching lines @@
 
 RenderWidgetHostView* RenderFrameHostManager::GetRenderWidgetHostView() const {
   if (interstitial_page_)
     return interstitial_page_->GetView();
   if (render_frame_host_)
     return render_frame_host_->GetView();
   return nullptr;
 }
 
 bool RenderFrameHostManager::ForInnerDelegate() {
-  // TODO(lazyboy): Subframes inside inner WebContents needs to be tested and
-  // we have to make sure that IsMainFrame() check below is appropriate. See
-  // http://crbug.com/500957.
-  return frame_tree_node_->IsMainFrame() &&
-         delegate_->GetOuterDelegateFrameTreeNodeID() !=
-             FrameTreeNode::kFrameTreeNodeInvalidID;
+  return delegate_->GetOuterDelegateFrameTreeNodeID() !=
+      FrameTreeNode::kFrameTreeNodeInvalidID;
 }
 
 RenderWidgetHostImpl*
 RenderFrameHostManager::GetOuterRenderWidgetHostForKeyboardInput() {
-  if (!ForInnerDelegate())
+  if (!ForInnerDelegate() || !frame_tree_node_->IsMainFrame())
     return nullptr;
 
   FrameTreeNode* outer_contents_frame_tree_node =
       FrameTreeNode::GloballyFindByID(
           delegate_->GetOuterDelegateFrameTreeNodeID());
   return outer_contents_frame_tree_node->parent()
       ->current_frame_host()
       ->render_view_host();
 }
 
@@ skipping 1493 matching lines @@
     proxy->set_render_frame_proxy_created(true);
   } else {
     proxy->InitRenderFrameProxy();
   }
 
   return proxy->GetRoutingID();
 }
 
 void RenderFrameHostManager::CreateProxiesForChildFrame(FrameTreeNode* child) {
   for (const auto& pair : *proxy_hosts_) {
+    // Do not create proxies for subframes in the outer delegate's process,
+    // since the outer delegate does not need to interact with them.
+    if (ForInnerDelegate() && GetProxyToOuterDelegate() == pair.second)

[lazyboy, 2015/07/30 19:46:32]

FYI, for
    A
   /
  B
 /
C

When C is added we would end up here (with this~=B), but B won't have a proxy to
outer delegate.
So checking for IsMainFrame() is not necessary.

[Charlie Reis, 2015/07/31 18:44:08]

Thanks.

nit: pair.second == GetProxyToOuterDelegate() seems more natural to read for the
second condition.

[lazyboy, 2015/07/31 19:21:41]

Done.

+      continue;
+
     child->render_manager()->CreateRenderFrameProxy(
         pair.second->GetSiteInstance());
   }
 }
 
 void RenderFrameHostManager::EnsureRenderViewInitialized(
     RenderViewHostImpl* render_view_host,
     SiteInstance* instance) {
   DCHECK(frame_tree_node_->IsMainFrame());
 
@@ skipping 31 matching lines @@
   // TODO(lazyboy): This |is_loading| behavior might not be what we want,
   // investigate and fix.
   render_frame_host->Send(new FrameMsg_SwapOut(
       render_frame_host->GetRoutingID(), proxy->GetRoutingID(),
       false /* is_loading */, FrameReplicationState()));
   proxy->set_render_frame_proxy_created(true);
 }
 
 void RenderFrameHostManager::SetRWHViewForInnerContents(
     RenderWidgetHostView* child_rwhv) {
-  DCHECK(ForInnerDelegate());
+  DCHECK(ForInnerDelegate() && frame_tree_node_->IsMainFrame());
   GetProxyToOuterDelegate()->SetChildRWHView(child_rwhv);
 }
 
 bool RenderFrameHostManager::InitRenderView(
     RenderViewHostImpl* render_view_host,
     int proxy_routing_id,
     bool for_main_frame_navigation) {
   // Ensure the renderer process is initialized before creating the
   // RenderView.
   if (!render_view_host->GetProcess()->Init())
@@ skipping 584 matching lines @@
 int RenderFrameHostManager::GetOpenerRoutingID(SiteInstance* instance) {
   if (!frame_tree_node_->opener())
     return MSG_ROUTING_NONE;
 
   return frame_tree_node_->opener()
       ->render_manager()
       ->GetRoutingIdForSiteInstance(instance);
 }
 
 }  // namespace content