Perform navigation policy check on UI thread for --site-per-process.

content/browser/frame_host/navigator_impl.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/navigator_impl.h"
 
 #include "base/command_line.h"
 #include "content/browser/frame_host/frame_tree.h"
 #include "content/browser/frame_host/frame_tree_node.h"
 #include "content/browser/frame_host/navigation_controller_impl.h"
@@ skipping 119 matching lines @@
 }  // namespace
 
 
 NavigatorImpl::NavigatorImpl(
     NavigationControllerImpl* navigation_controller,
     NavigatorDelegate* delegate)
     : controller_(navigation_controller),
       delegate_(delegate) {
 }
 
+NavigationController* NavigatorImpl::GetController() {
+  return controller_;
+}
+
 void NavigatorImpl::DidStartProvisionalLoad(
     RenderFrameHostImpl* render_frame_host,
     int parent_routing_id,
     const GURL& url) {
   bool is_error_page = (url.spec() == kUnreachableWebDataURL);
   bool is_iframe_srcdoc = (url.spec() == kAboutSrcDocURL);
   GURL validated_url(url);
   RenderProcessHost* render_process_host = render_frame_host->GetProcess();
   render_process_host->FilterURL(false, &validated_url);
 
@@ skipping 460 matching lines @@
 
     // Navigations in Web UI pages count as browser-initiated navigations.
     params.is_renderer_initiated = false;
   }
 
   if (delegate_)
     delegate_->RequestOpenURL(render_frame_host, params);
 }
 
 }  // namespace content