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

content/browser/frame_host/render_frame_host_impl.h

 // 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.
 
 #ifndef CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_IMPL_H_
 #define CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_IMPL_H_
 
 #include <string>
 
+#include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/render_frame_host.h"
 
 class GURL;
 struct FrameHostMsg_DidFailProvisionalLoadWithError_Params;
 
 namespace base {
 class FilePath;
 }
@@ skipping 51 matching lines @@
 
   // Hack to get this subframe to swap out, without yet moving over all the
   // SwapOut state and machinery from RenderViewHost.
   void SwapOut();
   void OnSwappedOut(bool timed_out);
   bool is_swapped_out() { return is_swapped_out_; }
   void set_swapped_out(bool is_swapped_out) {
     is_swapped_out_ = is_swapped_out;
   }
 
+  // Sets the RVH for |this| as pending shutdown. |on_swap_out| will be called
+  // when the swap out ack is received.

[Charlie Reis, 2014/01/31 19:11:55]

nit: SwapOutACK

[clamy, 2014/02/05 14:21:42]

Done.

+  void SetPendingShutdown(const base::Closure& on_swap_out);
+
  protected:
   friend class RenderFrameHostFactory;
 
   // TODO(nasko): Remove dependency on RenderViewHost here. RenderProcessHost
   // should be the abstraction needed here, but we need RenderViewHost to pass
   // into WebContentsObserver::FrameDetached for now.
   RenderFrameHostImpl(RenderViewHostImpl* render_view_host,
                       RenderFrameHostDelegate* delegate,
                       FrameTree* frame_tree,
                       FrameTreeNode* frame_tree_node,
@@ skipping 48 matching lines @@
 
   int routing_id_;
   bool is_swapped_out_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderFrameHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_IMPL_H_