Detach RemoteFrame from the tree when deleting RenderFrameProxy.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 0773d410a668139f071d9f8a13140f3ce6ba9f59..1ebf72aec18b07e25790ee75cc8a8bc7b5ee227a 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -598,6 +598,9 @@ RenderFrameImpl::~RenderFrameImpl() {
     render_view_->UnregisterVideoHoleFrame(this);
 #endif
 
+  if (render_frame_proxy_)
+    delete render_frame_proxy_;
+
   render_view_->UnregisterRenderFrame(this);
   g_routing_id_frame_map.Get().erase(routing_id_);
   RenderThread::Get()->RemoveRoute(routing_id_);