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

components/html_viewer/layout_test_content_handler_impl.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_HTML_VIEWER_LAYOUT_TEST_CONTENT_HANDLER_IMPL_H_
 #define COMPONENTS_HTML_VIEWER_LAYOUT_TEST_CONTENT_HANDLER_IMPL_H_
 
 #include "base/macros.h"
 #include "components/html_viewer/content_handler_impl.h"
 #include "components/html_viewer/html_factory.h"
 #include "components/test_runner/web_test_proxy.h"
 
 namespace blink {
 class WebView;
 }
 
 namespace test_runner {
 class WebTestInterfaces;
 }
 
 namespace html_viewer {
 
 class WebTestDelegateImpl;
 
 class LayoutTestContentHandlerImpl : public ContentHandlerImpl,
                                      public HTMLFactory {
  public:
   LayoutTestContentHandlerImpl(GlobalState* global_state,
-                               mojo::ApplicationImpl* app,
+                               mojo::Shell* shell,
                                mojo::InterfaceRequest<ContentHandler> request,
                                test_runner::WebTestInterfaces* test_interfaces,
                                WebTestDelegateImpl* test_delegate);
   ~LayoutTestContentHandlerImpl() override;
 
  private:
   using WebWidgetProxy =
       test_runner::WebTestProxy<HTMLWidgetRootLocal,
                                 HTMLWidgetRootLocal::CreateParams*>;
 
@@ skipping 12 matching lines @@
   WebTestDelegateImpl* test_delegate_;
   WebWidgetProxy* web_widget_proxy_;
   scoped_ptr<mojo::AppRefCount> app_refcount_;
 
   DISALLOW_COPY_AND_ASSIGN(LayoutTestContentHandlerImpl);
 };
 
 }  // namespace html_viewer
 
 #endif  // COMPONENTS_HTML_VIEWER_LAYOUT_TEST_CONTENT_HANDLER_IMPL_H_