Don't let swappedout:// page be visible when updating frame tree.

content/renderer/render_view_impl.cc

 // 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.
 
 #include "content/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <string>
 #include <vector>
@@ skipping 3778 matching lines @@
 
   int remote_id;
   if (frame_tree->GetInteger(content::kFrameTreeNodeIdKey, &remote_id))
     active_frame_id_map_.insert(std::pair<int, int>(frame->identifier(),
                                                     remote_id));
 
   ListValue* children;
   if (!frame_tree->GetList(content::kFrameTreeNodeSubtreeKey, &children))
     return;
 
+  // Create an invisible iframe tree in the swapped out page.
   base::DictionaryValue* child;
   for (size_t i = 0; i < children->GetSize(); ++i) {
     if (!children->GetDictionary(i, &child))
       continue;
     WebElement element = frame->document().createElement("iframe");
+    element.setAttribute("width", "0");
+    element.setAttribute("height", "0");
+    element.setAttribute("frameBorder", "0");
     if (frame->document().body().appendChild(element)) {
       WebFrame* subframe = WebFrame::fromFrameOwnerElement(element);
       if (subframe)
         CreateFrameTree(subframe, child);
     } else {
       LOG(ERROR) << "Failed to append created iframe element.";
     }
   }
 }
 
@@ skipping 2321 matching lines @@
   DCHECK(!java_bridge_dispatcher_);
 #if defined(ENABLE_JAVA_BRIDGE)
   java_bridge_dispatcher_ = new JavaBridgeDispatcher(this);
 #endif
 }
 
 void RenderViewImpl::OnUpdatedFrameTree(
     int process_id,
     int route_id,
     const std::string& frame_tree) {
+  // We should only act on this message if we are swapped out.  It's possible
+  // for this to happen due to races.
+  if (!is_swapped_out_)
+    return;
+
   base::DictionaryValue* frames = NULL;
   scoped_ptr<base::Value> tree(base::JSONReader::Read(frame_tree));
   if (tree.get() && tree->IsType(base::Value::TYPE_DICTIONARY))
     tree->GetAsDictionary(&frames);
 
   updating_frame_tree_ = true;
   active_frame_id_map_.clear();
 
   target_process_id_ = process_id;
   target_routing_id_ = route_id;
   CreateFrameTree(webview()->mainFrame(), frames);
 
   updating_frame_tree_ = false;
 }