Remove usage of RenderViewHost which aren't needed anymore.

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 281 matching lines @@
   RenderViewHostMap::iterator iter =
       render_view_host_map_.find(site_instance->GetId());
   // TODO(creis): Mirror the frame tree so this check can't fail.
   if (iter == render_view_host_map_.end())
     return NULL;
   return iter->second;
 }
 
 void FrameTree::RegisterRenderFrameHost(
     RenderFrameHostImpl* render_frame_host) {
-  SiteInstance* site_instance =
-      render_frame_host->render_view_host()->GetSiteInstance();
+  SiteInstance* site_instance = render_frame_host->GetSiteInstance();
   RenderViewHostMap::iterator iter =
       render_view_host_map_.find(site_instance->GetId());
   CHECK(iter != render_view_host_map_.end());
 
   iter->second->increment_ref_count();
 }
 
 void FrameTree::UnregisterRenderFrameHost(
     RenderFrameHostImpl* render_frame_host) {
-  SiteInstance* site_instance =
-      render_frame_host->render_view_host()->GetSiteInstance();
+  SiteInstance* site_instance = render_frame_host->GetSiteInstance();
   int32 site_instance_id = site_instance->GetId();
   RenderViewHostMap::iterator iter =
       render_view_host_map_.find(site_instance_id);
   if (iter != render_view_host_map_.end() &&
       iter->second == render_frame_host->render_view_host()) {
     // Decrement the refcount and shutdown the RenderViewHost if no one else is
     // using it.
     CHECK_GT(iter->second->ref_count(), 0);
     iter->second->decrement_ref_count();
     if (iter->second->ref_count() == 0) {
@@ skipping 22 matching lines @@
         rvh->Shutdown();
         render_view_host_pending_shutdown_map_.erase(multi_iter);
       }
       break;
     }
     CHECK(render_view_host_found);
   }
 }
 
 }  // namespace content