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

content/browser/renderer_host/render_view_host_impl.h

 // Copyright (c) 2012 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_RENDERER_HOST_RENDER_VIEW_HOST_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_IMPL_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 277 matching lines @@
   // page, making it unsafe to show the pending URL.  Always false after the
   // first commit.
   bool has_accessed_initial_document() {
     return has_accessed_initial_document_;
   }
 
   // Whether this RenderViewHost has been swapped out to be displayed by a
   // different process.
   bool is_swapped_out() const { return is_swapped_out_; }
 
+  // Whether this RenderViewHost is waiting for the execution of the unload in
+  // the background, and should not be destroyed on SwapOut, even if it was the
+  // last active in the SiteInstance.
+  bool should_be_preserved_on_swap_out() const {

[Charlie Reis, 2013/12/09 20:12:29]

I don't think we need these.

+    return should_be_preserved_on_swap_out_;
+  }
+
+  // Whether this RenderViewHostImpl needs to perform additional cleanup before
+  // being deleted. This is the case if the renderer was left to execute the
+  // unload event in the background.
+  bool need_to_perform_clean_up_on_swapped_out() const {
+    return need_to_perform_clean_up_on_swapped_out_;
+  }
+
   // Called on the pending RenderViewHost when the network response is ready to
   // commit.  We should ensure that the old RenderViewHost runs its unload
   // handler and determine whether a transfer to a different RenderViewHost is
   // needed.
   void OnCrossSiteResponse(
       const GlobalRequestID& global_request_id,
       bool is_transfer,
       const std::vector<GURL>& transfer_url_chain,
       const Referrer& referrer,
       PageTransition page_transition,
       int64 frame_id,
       bool should_replace_current_entry);
 
   // Tells the renderer that this RenderView will soon be swapped out, and thus
   // not to create any new modal dialogs until it happens.  This must be done
   // separately so that the PageGroupLoadDeferrers of any current dialogs are no
   // longer on the stack when we attempt to swap it out.
   void SuppressDialogsUntilSwapOut();
 
   // Tells the renderer that this RenderView is being swapped out for one in a
   // different renderer process.  It should run its unload handler and move to
   // a blank document.  The renderer should preserve the Frame object until it
   // exits, in case we come back.  The renderer can exit if it has no other
   // active RenderViews, but not until WasSwappedOut is called (when it is no
   // longer visible).
   void SwapOut();
 
   // Called when either the SwapOut request has been acknowledged or has timed
   // out.
-  void OnSwappedOut(bool timed_out);
+  void OnSwappedOut(bool timed_out, bool preserve_render_view_host);

[Charlie Reis, 2013/12/09 20:12:29]

I think we can get rid of this whole method.

 
   // Called to notify the renderer that it has been visibly swapped out and
   // replaced by another RenderViewHost, after an earlier call to SwapOut.
   // It is now safe for the process to exit if there are no other active
   // RenderViews.
   void WasSwappedOut();
 
   // Close the page ignoring whether it has unload events registers.
   // This is called after the beforeunload and unload events have fired
   // and the user has agreed to continue with closing the page.
@@ skipping 363 matching lines @@
   // ensures we don't spam the renderer with multiple beforeunload requests.
   // When either this value or is_waiting_for_unload_ack_ is true, the value of
   // unload_ack_is_for_cross_site_transition_ indicates whether this is for a
   // cross-site transition or a tab close attempt.
   bool is_waiting_for_beforeunload_ack_;
 
   // Set to true when there is a pending ViewMsg_Close message.  Also see
   // is_waiting_for_beforeunload_ack_, unload_ack_is_for_cross_site_transition_.
   bool is_waiting_for_unload_ack_;
 
+  // Set to true to prevent |this| to be killed when swapping out
+  // RenderViewHosts. This allows the unload handler to be run into background.
+  bool should_be_preserved_on_swap_out_;
+
+  // Set to true to have the renderer perform additional clean up if it had the
+  // unload handler run into the background previously.
+  bool need_to_perform_clean_up_on_swapped_out_;
+
   // Set to true when waiting for ViewHostMsg_SwapOut_ACK has timed out.
   bool has_timed_out_on_unload_;
 
   // Valid only when is_waiting_for_beforeunload_ack_ or
   // is_waiting_for_unload_ack_ is true.  This tells us if the unload request
   // is for closing the entire tab ( = false), or only this RenderViewHost in
   // the case of a cross-site transition ( = true).
   bool unload_ack_is_for_cross_site_transition_;
 
   bool are_javascript_messages_suppressed_;
@@ skipping 26 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(RenderViewHostImpl);
 };
 
 #if defined(COMPILER_MSVC)
 #pragma warning(pop)
 #endif
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_IMPL_H_