Execute BeforeUnload on subframe browser-initiated navigations

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 7b5b70b4f2c14352e66aa7114a3fdb14be329f2f..082830172607e09c6872832a6e799e0c799db273 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -1658,11 +1658,6 @@ void RenderFrameImpl::SetPendingNavigationParams(
 void RenderFrameImpl::OnBeforeUnload(bool is_reload) {
   TRACE_EVENT1("navigation,rail", "RenderFrameImpl::OnBeforeUnload",
                "id", routing_id_);
-  // TODO(creis): Right now, this is only called on the main frame.  Make the
-  // browser process send dispatchBeforeUnloadEvent to every frame that needs
-  // it.
-  CHECK(!frame_->parent());
-
   // Save the routing_id, as the RenderFrameImpl can be deleted in
   // dispatchBeforeUnloadEvent. See https://crbug.com/666714 for details.
   int routing_id = routing_id_;