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..82788069966688f2f4f3ce7a8c7dea2859e957a1 100644
--- a/content/browser/frame_host/render_frame_proxy_host.cc
+++ b/content/browser/frame_host/render_frame_proxy_host.cc
@@ -55,12 +55,16 @@ RenderFrameProxyHost::RenderFrameProxyHost(SiteInstance* site_instance,
       std::make_pair(
           RenderFrameProxyHostID(GetProcess()->GetID(), routing_id_),
           this)).second);
-
-  if (!frame_tree_node_->IsMainFrame() &&
-      frame_tree_node_->parent()
-              ->render_manager()
-              ->current_frame_host()
-              ->GetSiteInstance() == site_instance) {
+  bool is_proxy_to_parent = !frame_tree_node_->IsMainFrame() &&
+       frame_tree_node_->parent()
+               ->render_manager()
+               ->current_frame_host()
+               ->GetSiteInstance() == site_instance;
+
+  // If this is a proxy to parent frame or this proxy is for the inner
+  // WebContents' FTN in outer WebContents' process, then we need a

[Charlie Reis, 2015/05/22 23:44:31]

nit: WebContents's 
nit: FrameTreeNode

[lazyboy, 2015/05/26 16:32:54]

Done.

+  // CrossProcessFrameConnector.
+  if (is_proxy_to_parent || 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 +96,20 @@ 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.

[nasko, 2015/05/22 16:32:27]

I have a CL that does just that, but got reverted. Let's make sure we stay in
sync on that.

[lazyboy, 2015/05/26 16:32:54]

This function has been moved now.

 RenderViewHostImpl* RenderFrameProxyHost::GetRenderViewHost() {
-  return frame_tree_node_->frame_tree()->GetRenderViewHost(
-      site_instance_.get());
+  // RVH of outer WebContents' SiteInstance does not live in the RFHM of the

[nasko, 2015/05/22 16:32:27]

Hmmm, this strikes me as odd and possibly wrong. A proxy is associated with a
RVH in the same FrameTree. Each FrameTree should be self contained and we
shouldn't be bridging them here. The only true link between the two should be
the CrossProcessFrameConnector.

[Charlie Reis, 2015/05/22 23:44:31]

+1.  The RVH for a proxy should be in the same tree.

If you need the RVH from the outer WebContents, that should be a different
method.

[lazyboy, 2015/05/26 16:32:54]

This is required because RWHVChildFrame needed to
access the parent widget to read the last keyboard event.
See CPFC::OnForwardInputEvent().
However, during review cycle I broke keyboard events in this
CL and this was basically returning not the RVH I meant.
I've fixed keyboard events now, will add a test for that.
Since this is only used for keyboard, I've created a new
function that does that and made it obvious that it's only
used for keyboard events.

+  // inner WebContents, we need to look it up in the FrameTree of the outer
+  // WebContents.
+  RenderFrameProxyHost* proxy_to_outer_contents =
+      frame_tree_node_->render_manager()->GetProxyToOuterContents();
+  FrameTree* frame_tree =
+      proxy_to_outer_contents &&
+              proxy_to_outer_contents->GetSiteInstance() == GetSiteInstance()
+          ? proxy_to_outer_contents->frame_tree_node_->frame_tree()
+          : frame_tree_node_->frame_tree();
+  return frame_tree->GetRenderViewHost(site_instance_.get());
 }
 
 void RenderFrameProxyHost::TakeFrameHostOwnership(