Fix support for multiple frames per SiteInstance in CreateProxiesForSiteInstance

content/browser/frame_host/frame_tree.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/frame_tree.h"
 
 #include <queue>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 36 matching lines @@
 // given RenderViewHost's process.
 bool ResetNodesForNewProcess(RenderViewHost* render_view_host,
                              FrameTreeNode* node) {
   if (render_view_host == node->current_frame_host()->render_view_host())
     node->ResetForNewProcess();
   return true;
 }
 
 bool CreateProxyForSiteInstance(const scoped_refptr<SiteInstance>& instance,
                                 FrameTreeNode* node) {
-  node->render_manager()->CreateRenderFrameProxy(instance.get());
+  // If a new frame is created in an existing SiteInstance, the other frames in
+  // that SiteInstance don't need a proxy for the new frame.
+  SiteInstance* current_instance =
+      node->render_manager()->current_frame_host()->GetSiteInstance();

[Charlie Reis, 2014/10/21 22:31:27]

What about the SiteInstances that already have RenderFrameProxyHosts on the
proxy_hosts_ list?  Those would also qualify as "existing SiteInstance."

+  if (current_instance != instance.get()) {

[nasko, 2014/10/21 22:25:23]

nit: one line if statements don't need {}

+    node->render_manager()->CreateRenderFrameProxy(instance.get());
+  }
   return true;
 }
 
 }  // namespace
 
 FrameTree::FrameTree(Navigator* navigator,
                      RenderFrameHostDelegate* render_frame_delegate,
                      RenderViewHostDelegate* render_view_delegate,
                      RenderWidgetHostDelegate* render_widget_delegate,
                      RenderFrameHostManager::Delegate* manager_delegate)
@@ skipping 272 matching lines @@
         rvh->Shutdown();
         render_view_host_pending_shutdown_map_.erase(multi_iter);
       }
       break;
     }
     CHECK(render_view_host_found);
   }
 }
 
 }  // namespace content