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

mojo/services/test_service/test_request_tracker_application.h

 // Copyright 2014 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 SERVICES_TEST_SERVICE_TEST_REQUEST_TRACKER_APPLICATION_H_
 #define SERVICES_TEST_SERVICE_TEST_REQUEST_TRACKER_APPLICATION_H_
 
 #include "mojo/public/cpp/system/macros.h"
 #include "mojo/services/test_service/test_request_tracker_impl.h"
 #include "mojo/shell/public/cpp/application_delegate.h"
 #include "mojo/shell/public/cpp/interface_factory_impl.h"
 
 namespace mojo {
 class ApplicationImpl;
 namespace test {
 class TestTimeService;
 
 // Embeds TestRequestTracker mojo services into an application.
 class TestRequestTrackerApplication
     : public ApplicationDelegate,
       public InterfaceFactory<TestTimeService>,
       public InterfaceFactory<TestRequestTracker>,
       public InterfaceFactory<TestTrackedRequestService> {
  public:
   TestRequestTrackerApplication();
   ~TestRequestTrackerApplication() override;
 
-  void Initialize(ApplicationImpl* app) override;
-
   // ApplicationDelegate methods:
+  void Initialize(Shell* shell, const std::string& url, uint32_t id) override;
   bool AcceptConnection(ApplicationConnection* connection) override;
 
   // InterfaceFactory<TestTimeService> methods:
   void Create(ApplicationConnection* connection,
               InterfaceRequest<TestTimeService> request) override;
 
   // InterfaceFactory<TestRequestTracker> methods:
   void Create(ApplicationConnection* connection,
               InterfaceRequest<TestRequestTracker> request) override;
 
   // InterfaceFactory<TestTrackedRequestService> methods:
   void Create(ApplicationConnection* connection,
               InterfaceRequest<TestTrackedRequestService> request) override;
 
  private:
-  ApplicationImpl* app_impl_;
+  Shell* shell_;
   TrackingContext context_;
   MOJO_DISALLOW_COPY_AND_ASSIGN(TestRequestTrackerApplication);
 };
 
 }  // namespace test
 }  // namespace mojo
 
 #endif  // SERVICES_TEST_SERVICE_TEST_REQUEST_TRACKER_APPLICATION_H_