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

content/browser/frame_host/interstitial_page_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/interstitial_page_navigator_impl.h"
 
 #include "content/browser/frame_host/interstitial_page_impl.h"
+#include "content/browser/frame_host/navigation_controller_impl.h"
 #include "content/browser/frame_host/navigator_delegate.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 
 namespace content {
 
 InterstitialPageNavigatorImpl::InterstitialPageNavigatorImpl(
     InterstitialPageImpl* interstitial,
     NavigationControllerImpl* navigation_controller)
-    : interstitial_(interstitial) {}
+    : interstitial_(interstitial),
+      controller_(navigation_controller) {}
+
+NavigationController* InterstitialPageNavigatorImpl::GetController() {
+  return controller_;
+}
 
 void InterstitialPageNavigatorImpl::DidNavigate(
     RenderFrameHostImpl* render_frame_host,
     const FrameHostMsg_DidCommitProvisionalLoad_Params& input_params) {
   // TODO(nasko): Move implementation here, but for the time being call out
   // to the interstitial page code.
   interstitial_->DidNavigate(
       render_frame_host->render_view_host(), input_params);
 }
 
 }  // namespace content