Ensure RenderViewHost is not shut down until a screenshot of the page is taken.

content/browser/frame_host/render_frame_host_manager.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_manager.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 482 matching lines @@
        iter != swapped_out_hosts_.end();
        ++iter) {
     DCHECK_NE(iter->second->render_view_host()->GetSiteInstance(),
               current_host()->GetSiteInstance());
     iter->second->render_view_host()->DisownOpener();
   }
 }
 
 void RenderFrameHostManager::RendererProcessClosing(
     RenderProcessHost* render_process_host) {
-  // Remove any swapped out RVHs from this process, so that we don't try to
+  // Remove any swapped out RFHs from this process, so that we don't try to
   // swap them back in while the process is exiting.  Start by finding them,
   // since there could be more than one.
   std::list<int> ids_to_remove;
   for (RenderFrameHostMap::iterator iter = swapped_out_hosts_.begin();
        iter != swapped_out_hosts_.end();
        ++iter) {
     if (iter->second->GetProcess() == render_process_host)
       ids_to_remove.push_back(iter->first);
   }
 
   // Now delete them.
   while (!ids_to_remove.empty()) {
-    delete swapped_out_hosts_[ids_to_remove.back()];
+    RenderFrameHostImpl* rfh = swapped_out_hosts_[ids_to_remove.back()];
+    // The pending RFH may be on the swapped out list if we started to swap it
+    // back in.
+    if (rfh == pending_render_frame_host_.get()) {
+      CancelPending();

[mfomitchev, 2014/03/26 18:59:30]

I had to add this code because without it one of the unit tests was hitting
NOTREACHED() in RenderFrameHostManager::RenderViewDeleted(). It looks like this
is legit problem that needed fixing regardless of the rest of the change.

[nasko, 2014/03/26 22:48:27]

Can you share which test that was?

[mfomitchev, 2014/03/27 21:51:34]

IsolatedAppTest.CrossProcessClientRedirect. At the end of the test there is a
navigation via JavaScript and then right after that GoBack(). With the new
behavior, the swapped out host becomes the pending host before it is destroyed.
That said, I think this could occur before the change as well - e.g. see comment
in CancelPending() line 1382 of the original file.

+      //pending_render_frame_host_.reset();

[nasko, 2014/03/26 22:48:27]

You don't need a reset here, CancelPending will take care of the pending RFH.

[mfomitchev, 2014/03/27 21:51:34]

Done.

+    } else {
+      delete swapped_out_hosts_[ids_to_remove.back()];
+    }
     swapped_out_hosts_.erase(ids_to_remove.back());
     ids_to_remove.pop_back();
   }
 }
 
 void RenderFrameHostManager::SwapOutOldPage() {
   // Should only see this while we have a pending renderer or transfer.
   CHECK(cross_navigation_pending_ || pending_nav_params_.get());
 
   // Tell the renderer to suppress any further modal dialogs so that we can swap
@@ skipping 936 matching lines @@
     SiteInstance* instance) const {
   RenderFrameHostMap::const_iterator iter =
       swapped_out_hosts_.find(instance->GetId());
   if (iter != swapped_out_hosts_.end())
     return iter->second;
 
   return NULL;
 }
 
 }  // namespace content