Make RenderFrame(Host) own a RenderWidget(Host).

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index af0c6fcc9a43af5997fc99815ca11e7f44696bee..6157b7010d9396602ca2f156eb0f7fe2086b6076 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -119,6 +119,7 @@ RenderFrameHostImpl* RenderFrameHostImpl::FromID(int process_id,
 
 RenderFrameHostImpl::RenderFrameHostImpl(RenderViewHostImpl* render_view_host,
                                          RenderFrameHostDelegate* delegate,
+                                         RenderWidgetHostDelegate* rwh_delegate,
                                          FrameTree* frame_tree,
                                          FrameTreeNode* frame_tree_node,
                                          int routing_id,
@@ -139,6 +140,7 @@ RenderFrameHostImpl::RenderFrameHostImpl(RenderViewHostImpl* render_view_host,
       no_create_browser_accessibility_manager_for_testing_(false),
       weak_ptr_factory_(this) {
   bool is_swapped_out = !!(flags & CREATE_RF_SWAPPED_OUT);
+  bool hidden = !!(flags & CREATE_RF_HIDDEN);
   frame_tree_->RegisterRenderFrameHost(this);
   GetProcess()->AddRoute(routing_id_, this);
   g_routing_id_frame_map.Get().insert(std::make_pair(
@@ -155,6 +157,12 @@ RenderFrameHostImpl::RenderFrameHostImpl(RenderViewHostImpl* render_view_host,
   SetUpMojoIfNeeded();
   swapout_event_monitor_timeout_.reset(new TimeoutMonitor(base::Bind(
       &RenderFrameHostImpl::OnSwappedOut, weak_ptr_factory_.GetWeakPtr())));
+
+  if (flags & CREATE_RF_NEEDS_RENDER_WIDGET_HOST) {
+    render_widget_host_.reset(new RenderWidgetHostImpl(
+        rwh_delegate, GetProcess(), MSG_ROUTING_NONE, hidden));
+    render_widget_host_->InitForFrame();
+  }
 }
 
 RenderFrameHostImpl::~RenderFrameHostImpl() {
@@ -509,7 +517,29 @@ bool RenderFrameHostImpl::CreateRenderFrame(int parent_routing_id,
 
   DCHECK(GetProcess()->HasConnection());
 
-  Send(new FrameMsg_NewFrame(routing_id_, parent_routing_id, proxy_routing_id));
+  FrameMsg_NewFrame_WidgetParams widget_params;
+  if (render_widget_host_) {
+    widget_params.routing_id = render_widget_host_->GetRoutingID();
+    widget_params.surface_id = render_widget_host_->surface_id();
+    widget_params.hidden = render_widget_host_->is_hidden();
+  } else {
+    // MSG_ROUTING_NONE will prevent a new RenderWidget from being created in
+    // the renderer process.
+    widget_params.routing_id = MSG_ROUTING_NONE;
+    widget_params.surface_id = 0;
+    widget_params.hidden = true;
+  }
+
+  Send(new FrameMsg_NewFrame(routing_id_, parent_routing_id, proxy_routing_id,
+                             widget_params));
+
+  // The RenderWidgetHost takes ownership of its view. It is tied to the
+  // lifetime of the current RenderProcessHost for this RenderFrameHost.
+  if (render_widget_host_) {
+    RenderWidgetHostView* rwhv =
+        new RenderWidgetHostViewChildFrame(render_widget_host_.get());
+    rwhv->Hide();
+  }
 
   // The renderer now has a RenderFrame for this RenderFrameHost.  Note that
   // this path is only used for out-of-process iframes.  Main frame RenderFrames
@@ -721,7 +751,27 @@ void RenderFrameHostImpl::OnDidDropNavigation() {
 }
 
 RenderWidgetHostImpl* RenderFrameHostImpl::GetRenderWidgetHost() {
-  return static_cast<RenderWidgetHostImpl*>(render_view_host_);
+  if (render_widget_host_)
+    return render_widget_host_.get();
+
+  // TODO(kenrb): When RenderViewHost no longer inherits RenderWidgetHost,
+  // we can remove this fallback. Currently it is only used for the main
+  // frame.
+  if (!GetParent())
+    return static_cast<RenderWidgetHostImpl*>(render_view_host_);
+
+  return nullptr;
+}
+
+RenderWidgetHostView* RenderFrameHostImpl::GetView() {
+  RenderFrameHostImpl* frame = this;
+  while (frame) {

[nasko, 2015/01/14 20:08:04]

Why is this method traversing up the parent chain and GetRenderWidgetHost isn't?

[kenrb, 2015/01/15 22:41:46]

The latter is intended to act mainly as an accessor, and I think it is more
likely to be useful to return NULL if the frame doesn't have one. GetView()
means that we intend to call Show() or Hide() on the RWHV, so more clearly needs
to return a valid object.

I might rethink this later. There is a difference between page level visibility
and frame level visibility that needs to be sorted out.

[nasko, 2015/01/15 23:11:15]

Acknowledged.

+    if (frame->render_widget_host_)
+      return frame->render_widget_host_->GetView();
+    frame = static_cast<RenderFrameHostImpl*>(frame->GetParent());
+  }
+
+  return render_view_host_->GetView();
 }
 
 int RenderFrameHostImpl::GetEnabledBindings() {