Drop CreateChildFrame messages when swapping out.

content/browser/frame_host/frame_tree_node.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_node.h"
 
 #include <queue>
 
 #include "base/command_line.h"
 #include "base/stl_util.h"
@@ skipping 30 matching lines @@
       switches::kEnableBrowserSideNavigation)) {
     navigator_->CancelNavigation(this);
   }
 }
 
 bool FrameTreeNode::IsMainFrame() const {
   return frame_tree_->root() == this;
 }
 
 void FrameTreeNode::AddChild(scoped_ptr<FrameTreeNode> child,
+                             int process_id,
                              int frame_routing_id) {
+  // Child frame must always be created in the same process as the parent.
+  CHECK_EQ(process_id, render_manager_.current_host()->GetProcess()->GetID());
+
   // Initialize the RenderFrameHost for the new node.  We always create child
   // frames in the same SiteInstance as the current frame, and they can swap to
   // a different one if they navigate away.
   child->render_manager()->Init(
       render_manager_.current_host()->GetSiteInstance()->GetBrowserContext(),
       render_manager_.current_host()->GetSiteInstance(),
       render_manager_.current_host()->GetRoutingID(),
       frame_routing_id);
   child->set_parent(this);
   children_.push_back(child.release());
@@ skipping 24 matching lines @@
   current_frame_host()->set_render_frame_created(false);
 
   // The children may not have been cleared if a cross-process navigation
   // commits before the old process cleans everything up.  Make sure the child
   // nodes get deleted before swapping to a new process.
   ScopedVector<FrameTreeNode> old_children = children_.Pass();
   old_children.clear();  // May notify observers.
 }
 
 }  // namespace content