Fix unresponsive tab closure when a navigation is in progress.

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 221 matching lines @@
   }
 }
 
 void RenderFrameHostManager::SetIsLoading(bool is_loading) {
   render_frame_host_->render_view_host()->SetIsLoading(is_loading);
   if (pending_render_frame_host_)
     pending_render_frame_host_->render_view_host()->SetIsLoading(is_loading);
 }
 
 bool RenderFrameHostManager::ShouldCloseTabOnUnresponsiveRenderer() {
-  if (!cross_navigation_pending_)
+  // If we're waiting for a close ACK, then the tab should close whether there's
+  // a navigation in progress or not.  Unfortunately, we also need to check for
+  // cases that we arrive here with no navigation in progress, since there are
+  // some tab closure paths that don't set is_waiting_for_close_ack to true.
+  // TODO(creis): Clean this up in http://crbug.com/418266.
+  if (!cross_navigation_pending_ ||
+      render_frame_host_->render_view_host()->is_waiting_for_close_ack())
     return true;
 
   // We should always have a pending RFH when there's a cross-process navigation
   // in progress.  Sanity check this for http://crbug.com/276333.
   CHECK(pending_render_frame_host_);
 
   // Unload handlers run in the background, so we should never get an
   // unresponsiveness warning for them.
   CHECK(!render_frame_host_->IsWaitingForUnloadACK());
 
@@ skipping 1335 matching lines @@
 void RenderFrameHostManager::DeleteRenderFrameProxyHost(
     SiteInstance* instance) {
   RenderFrameProxyHostMap::iterator iter = proxy_hosts_.find(instance->GetId());
   if (iter != proxy_hosts_.end()) {
     delete iter->second;
     proxy_hosts_.erase(iter);
   }
 }
 
 }  // namespace content