Extract shell methods from ApplicationImpl into a base class, and pass this to Initialize() instead.

components/web_view/public/cpp/web_view.h

 // Copyright 2015 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.
 
 #ifndef COMPONENTS_WEB_VIEW_PUBLIC_CPP_WEB_VIEW_H_
 #define COMPONENTS_WEB_VIEW_PUBLIC_CPP_WEB_VIEW_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "components/web_view/public/interfaces/web_view.mojom.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace mojo {
-class ApplicationImpl;
+class Shell;
 }
 
 namespace mus {
 class Window;
 }
 
 namespace web_view {
 
 class WebView {
  public:
   explicit WebView(mojom::WebViewClient* client);
   ~WebView();
 
-  void Init(mojo::ApplicationImpl* app, mus::Window* window);
+  void Init(mojo::Shell* shell, mus::Window* window);
 
   mojom::WebView* web_view() { return web_view_.get(); }
 
  private:
   mojom::WebViewPtr web_view_;
   mojo::Binding<mojom::WebViewClient> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(WebView);
 };
 
 }  // namespace web_view
 
 #endif  // COMPONENTS_WEB_VIEW_PUBLIC_CPP_WEB_VIEW_H_