OOPIF: Remove the FrameTreeNode when a RemoteFrame is detached.

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 988f9e876b4bdc989331f534aed27ff9014d36f5..597012084ead267fa2245ce8e8e0a2522433b333 100644
--- a/content/browser/frame_host/render_frame_proxy_host.cc
+++ b/content/browser/frame_host/render_frame_proxy_host.cc
@@ -116,6 +116,7 @@ bool RenderFrameProxyHost::OnMessageReceived(const IPC::Message& msg) {
 
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(RenderFrameProxyHost, msg)
+    IPC_MESSAGE_HANDLER(FrameHostMsg_Detach, OnDetach)
     IPC_MESSAGE_HANDLER(FrameHostMsg_OpenURL, OnOpenURL)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
@@ -157,8 +158,22 @@ void RenderFrameProxyHost::DisownOpener() {
   Send(new FrameMsg_DisownOpener(GetRoutingID()));
 }
 
+void RenderFrameProxyHost::OnDetach() {
+  // This message should only be received for subframes, and only from processes
+  // of its ancestor frames (which have the ability to remove it).
+  if (frame_tree_node_->IsMainFrame() ||
+      !frame_tree_node_->HasAncestorFrom(GetSiteInstance())) {
+    // TODO(creis): Use updated contract for ReceivedBadMessage.
+    GetProcess()->ReceivedBadMessage();
+    return;
+  }
+  frame_tree_node_->frame_tree()->RemoveFrame(frame_tree_node_);
+}
+
 void RenderFrameProxyHost::OnOpenURL(
     const FrameHostMsg_OpenURL_Params& params) {
+  // TODO(creis): Verify that we are in the same BrowsingInstance as the current
+  // RenderFrameHost.  See NavigatorImpl::RequestOpenURL.
   frame_tree_node_->current_frame_host()->OpenURL(params, site_instance_.get());
 }