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

content/browser/frame_host/render_frame_host_manager.cc

Index: content/browser/frame_host/render_frame_host_manager.cc
diff --git a/content/browser/frame_host/render_frame_host_manager.cc b/content/browser/frame_host/render_frame_host_manager.cc
index 18890339a74b76ed4f2293c1bc742e6372f42fb6..4f8a828a2b6d513a98ccbca2d7ad5e65e86cc3ed 100644
--- a/content/browser/frame_host/render_frame_host_manager.cc
+++ b/content/browser/frame_host/render_frame_host_manager.cc
@@ -263,9 +263,6 @@ RenderWidgetHostView* RenderFrameHostManager::GetRenderWidgetHostView() const {
 }
 
 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() &&

[Charlie Reis, 2015/07/28 22:36:02]

I still question whether this should return false for subframes in the guest. 
That seems like a confusing API: false most of the time, true for guest main
frames, but false for guest subframes.  The name of the method doesn't indicate
that.

It's also hard to tell whether some of the call sites of this method would do
the wrong thing if this returned false for subframes (e.g., in
CrossProcessFrameConnector).

Should it be up to the caller to check for the main frame if it matters, or is
it better to rename the method to be explicit about what it's doing (e.g.,
ForInnerDelegateMainFrame)?

Note: Either way, the .h file needs updating as well, since it has a TODO about
this.

[lazyboy, 2015/07/30 19:46:31]

I've made the function only care about its inner-ness and dropped the main frame
requirement.
I've gone on this route.
or is
Done.

          delegate_->GetOuterDelegateFrameTreeNodeID() !=
              FrameTreeNode::kFrameTreeNodeInvalidID;
@@ -1787,6 +1784,11 @@ int RenderFrameHostManager::CreateRenderFrameProxy(SiteInstance* instance) {
 
 void RenderFrameHostManager::CreateProxiesForChildFrame(FrameTreeNode* child) {
   for (const auto& pair : *proxy_hosts_) {
+    // If this proxy lives in our outer delegate process, then subframe

[Charlie Reis, 2015/07/28 22:36:02]

Rephrase:
Do not create proxies for subframes in the outer delegate's process, since the
outer delegate does not need to interact with them.

[lazyboy, 2015/07/30 19:46:31]

Done.

+    // FrameTreeNodes should not have proxy to that outer delegate.
+    if (ForInnerDelegate() && GetProxyToOuterDelegate() == pair.second)
+      continue;
+
     child->render_manager()->CreateRenderFrameProxy(
         pair.second->GetSiteInstance());
   }