OOPIF: Remove the FrameTreeNode when a RemoteFrame is detached.

content/renderer/render_frame_proxy.cc

Index: content/renderer/render_frame_proxy.cc
diff --git a/content/renderer/render_frame_proxy.cc b/content/renderer/render_frame_proxy.cc
index ae6d699ae739783c76a70f4dcb05fcd246c45949..76efc9184a01026899d8b7d12bffd08a1d1a95e1 100644
--- a/content/renderer/render_frame_proxy.cc
+++ b/content/renderer/render_frame_proxy.cc
@@ -307,6 +307,10 @@ void RenderFrameProxy::frameDetached() {
   if (web_frame_->parent())
     web_frame_->parent()->removeChild(web_frame_);
 
+  // Let the browser process know this frame is removed, so that it is destroyed
+  // in its current process.
+  Send(new FrameHostMsg_Detach(routing_id_));
+
   web_frame_->close();
   delete this;
 }