Move ownership of ChildFrameCompositingHelper from frame to proxy.

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 b09fccb5eab3cf49306a090122c953ceca60713c..2c84798fa2c2dcd1a5ead7da5146d30173cb4aef 100644
--- a/content/browser/frame_host/render_frame_proxy_host.cc
+++ b/content/browser/frame_host/render_frame_proxy_host.cc
@@ -4,8 +4,11 @@
 
 #include "content/browser/frame_host/render_frame_proxy_host.h"
 
+#include "content/browser/frame_host/cross_process_frame_connector.h"
 #include "content/browser/frame_host/frame_tree_node.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
+#include "content/browser/frame_host/render_widget_host_view_child_frame.h"
+#include "content/browser/renderer_host/render_widget_host_view_base.h"
 #include "content/browser/site_instance_impl.h"
 #include "content/common/frame_messages.h"
 #include "ipc/ipc_message.h"
@@ -18,6 +21,21 @@ RenderFrameProxyHost::RenderFrameProxyHost(SiteInstance* site_instance,
       site_instance_(site_instance),
       frame_tree_node_(frame_tree_node) {
   GetProcess()->AddRoute(routing_id_, this);
+
+  if (!frame_tree_node_->IsMainFrame() &&
+      frame_tree_node_->parent()
+              ->render_manager()
+              ->current_frame_host()
+              ->GetSiteInstance() == site_instance) {
+    // 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
+    // navigation, when the RenderFrameHost leaves the same process as its
+    // parent. The same CrossProcessFrameConnector is used for subsequent cross-
+    // process navigations, but it will be destroyed if the frame is
+    // navigated back to the same SiteInstance as its parent.
+    cross_process_frame_connector_.reset(new CrossProcessFrameConnector(this));
+  }
 }
 
 RenderFrameProxyHost::~RenderFrameProxyHost() {
@@ -27,6 +45,11 @@ RenderFrameProxyHost::~RenderFrameProxyHost() {
   GetProcess()->RemoveRoute(routing_id_);
 }
 
+void RenderFrameProxyHost::SetChildRWHView(RenderWidgetHostView* view) {
+  cross_process_frame_connector_->set_view(
+      static_cast<RenderWidgetHostViewChildFrame*>(view));
+}
+
 RenderViewHostImpl* RenderFrameProxyHost::GetRenderViewHost() {
   if (render_frame_host_.get())
     return render_frame_host_->render_view_host();
@@ -47,6 +70,10 @@ bool RenderFrameProxyHost::Send(IPC::Message *msg) {
 }
 
 bool RenderFrameProxyHost::OnMessageReceived(const IPC::Message& msg) {
+  if (cross_process_frame_connector_.get() &&
+      cross_process_frame_connector_->OnMessageReceived(msg))
+    return true;
+
   // TODO(nasko): This can be removed once we don't have a swapped out state on
   // RenderFrameHosts. See https://crbug.com/357747.
   if (render_frame_host_.get())