Make <webview> use out-of-process iframe architecture.

content/browser/frame_host/render_frame_proxy_host.cc

Index: content/browser/frame_host/render_frame_proxy_host.cc
diff --git a/content/browser/frame_host/render_frame_proxy_host.cc b/content/browser/frame_host/render_frame_proxy_host.cc
index 6d41f873516b9a088bb9d4fed4aa3eb8a267dc65..0d592fb3f5ac3215958c000aa7cb506384077e52 100644
--- a/content/browser/frame_host/render_frame_proxy_host.cc
+++ b/content/browser/frame_host/render_frame_proxy_host.cc
@@ -56,11 +56,14 @@ RenderFrameProxyHost::RenderFrameProxyHost(SiteInstance* site_instance,
           RenderFrameProxyHostID(GetProcess()->GetID(), routing_id_),
           this)).second);
 
-  if (!frame_tree_node_->IsMainFrame() &&
-      frame_tree_node_->parent()
-              ->render_manager()
-              ->current_frame_host()
-              ->GetSiteInstance() == site_instance) {
+  if ((!frame_tree_node_->IsMainFrame() &&
+       frame_tree_node_->parent()
+               ->render_manager()
+               ->current_frame_host()
+               ->GetSiteInstance() == site_instance) ||
+      // If this is a proxy for the guest FTN in its embedder process, then we
+      // need a CrossProcessFrameConnector.

[Charlie Reis, 2015/05/19 07:12:31]

This is getting a bit too complicated, given that there's comments within the
conditional itself.  Maybe we should split out the first half into a
is_proxy_to_parent bool and then move the comment before the conditional.

[lazyboy, 2015/05/21 23:23:47]

Done.

+      frame_tree_node_->render_manager()->IsGuest()) {
     // The RenderFrameHost navigating cross-process is destroyed and a proxy for
     // it is created in the parent's process. CrossProcessFrameConnector
     // initialization only needs to happen on an initial cross-process
@@ -92,9 +95,19 @@ void RenderFrameProxyHost::SetChildRWHView(RenderWidgetHostView* view) {
       static_cast<RenderWidgetHostViewChildFrame*>(view));
 }
 
+// TODO(lazyboy): We can probably cache a pointer to RVH in this class
+// as we do in RenderFrameHostImpl.
 RenderViewHostImpl* RenderFrameProxyHost::GetRenderViewHost() {
-  return frame_tree_node_->frame_tree()->GetRenderViewHost(
-      site_instance_.get());
+  // RVH of embedder SiteInstance does not live in the guest RFHM, we need to
+  // look it up in the embedder's FrameTree.
+  RenderFrameProxyHost* proxy_to_embedder =
+      frame_tree_node_->render_manager()->GetProxyToEmbedder();
+  FrameTree* frame_tree =
+      proxy_to_embedder &&
+              proxy_to_embedder->GetSiteInstance() == GetSiteInstance()
+          ? proxy_to_embedder->frame_tree_node_->frame_tree()
+          : frame_tree_node_->frame_tree();
+  return frame_tree->GetRenderViewHost(site_instance_.get());
 }
 
 void RenderFrameProxyHost::TakeFrameHostOwnership(