Have the unload event execute in background on cross-site navigations

content/browser/frame_host/render_frame_host_impl.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/frame_host/render_frame_host_impl.h"
 
 #include "base/containers/hash_tables.h"
 #include "base/lazy_instance.h"
 #include "content/browser/frame_host/cross_process_frame_connector.h"
 #include "content/browser/frame_host/frame_tree.h"
@@ skipping 176 matching lines @@
 }
 
 void RenderFrameHostImpl::OnSwapOutACK() {
   OnSwappedOut(false);
 }
 
 void RenderFrameHostImpl::OnSwappedOut(bool timed_out) {
   frame_tree_node_->render_manager()->SwappedOutFrame(this);
 }
 
+void RenderFrameHostImpl::SetPendingShutdown(const base::Closure& on_swap_out) {
+  render_view_host_->SetPendingShutdown(on_swap_out);
+}
+
 }  // namespace content