Extract minimal RenderViewHost interface for embedders, leaving

chrome/browser/ui/gtk/notifications/balloon_view_host_gtk.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 "chrome/browser/ui/gtk/notifications/balloon_view_host_gtk.h"
 
 #include <gtk/gtk.h>
 
 #include "chrome/browser/notifications/balloon.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
 
 BalloonViewHost::BalloonViewHost(Balloon* balloon)
     : BalloonHost(balloon) {
 }
 
 BalloonViewHost::~BalloonViewHost() {
   Shutdown();
 }
 
 void BalloonViewHost::UpdateActualSize(const gfx::Size& new_size) {
   RenderViewHost* host = web_contents_->GetRenderViewHost();
   if (host) {
-    content::RenderWidgetHostView* view = host->view();
+    content::RenderWidgetHostView* view = host->GetView();
     if (view)
       view->SetSize(new_size);
   }
 
   gtk_widget_set_size_request(
       native_view(), new_size.width(), new_size.height());
 }
 
 gfx::NativeView BalloonViewHost::native_view() const {
   return web_contents_->GetNativeView();
 }