PlzNavigate: improve tracking of improper subframe swap-out.

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/logging.h"
@@ skipping 647 matching lines @@
 
   // If the SiteInstance for the pending RFH is being used by others don't
   // delete the RFH. Just swap it out and it can be reused at a later point.
   SiteInstanceImpl* site_instance = render_frame_host->GetSiteInstance();
   if (site_instance->HasSite() && site_instance->active_frame_count() > 1) {
     // Any currently suspended navigations are no longer needed.
     render_frame_host->CancelSuspendedNavigations();
 
     RenderFrameProxyHost* proxy =
         new RenderFrameProxyHost(site_instance, frame_tree_node_);
+    CHECK(!GetRenderFrameProxyHost(site_instance));

[clamy, 2015/04/14 15:32:04]

Maybe move the CHECK above the creation of the new proxy?

[carlosk, 2015/04/23 16:10:13]

Done.

     proxy_hosts_[site_instance->GetId()] = proxy;
 
     // Check if the RenderFrameHost is already swapped out, to avoid swapping it
     // out again.
     if (!render_frame_host->is_swapped_out())
       render_frame_host->SwapOut(proxy, false);
 
     if (frame_tree_node_->IsMainFrame())
       proxy->TakeFrameHostOwnership(render_frame_host.Pass());
   } else {
@@ skipping 1407 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