OOPIF: Handle cross-site frames being blocked by X-Frame-Options or CSP.

content/browser/frame_host/navigator_impl.cc

Index: content/browser/frame_host/navigator_impl.cc
diff --git a/content/browser/frame_host/navigator_impl.cc b/content/browser/frame_host/navigator_impl.cc
index 6d63a274159f87f415bc02e76195d8e4c15d49f3..83033ab32dff3ab3b0b776968659cf6926bb6a3d 100644
--- a/content/browser/frame_host/navigator_impl.cc
+++ b/content/browser/frame_host/navigator_impl.cc
@@ -227,6 +227,22 @@ void NavigatorImpl::DidFailProvisionalLoadWithError(
     controller_->delegate()->NotifyNavigationStateChanged(INVALIDATE_TYPE_URL);
   }
 
+  // If this failure came from a pending RenderFrameHost rather than the
+  // current one, the current RenderFrameHost needs to be notified to stop
+  // its load.  Typically, the pending RenderFrameHost should be created only
+  // once the browser process is sure that it will commit, but there is a case
+  // where this is currently not true, which is when a cross-process frame is
+  // blocked by X-Frame-Options or CSP frame-ancestors.  This check will also
+  // guard against any future such cases.
+  //
+  // TODO(mkwst, alexmos): The case above should disappear when X-Frame-Options
+  // and CSP enforcement moves to the browser process
+  // (https://crbug.com/555418).
+  RenderFrameHostManager* manager =
+      render_frame_host->frame_tree_node()->render_manager();
+  if (render_frame_host == manager->pending_frame_host())
+    manager->current_frame_host()->Stop();
+
   if (delegate_)
     delegate_->DidFailProvisionalLoadWithError(render_frame_host, params);
 }