Add tracing service and make the shell+sky_viewer+services talk to it

mojo/services/surfaces/surfaces_service_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 MOJO_SERVICES_SURFACES_SURFACES_SERVICE_APPLICATION_H_
 #define MOJO_SERVICES_SURFACES_SURFACES_SERVICE_APPLICATION_H_
 
 #include "base/macros.h"
 #include "base/timer/timer.h"
 #include "cc/surfaces/surface_manager.h"
 #include "mojo/public/cpp/application/application_delegate.h"
 #include "mojo/public/cpp/application/interface_factory.h"
 #include "mojo/services/public/interfaces/surfaces/surfaces_service.mojom.h"
 #include "mojo/services/surfaces/surfaces_impl.h"
 
 namespace mojo {
 class ApplicationConnection;
 
 class SurfacesServiceApplication : public ApplicationDelegate,
                                    public InterfaceFactory<SurfacesService>,
                                    public SurfacesImpl::Client {
  public:
   SurfacesServiceApplication();
   ~SurfacesServiceApplication() override;
 
   // ApplicationDelegate implementation.
+  void Initialize(ApplicationImpl* app) override;
   bool ConfigureIncomingConnection(ApplicationConnection* connection) override;
 
   // InterfaceFactory<SurfacsServicee> implementation.
   void Create(ApplicationConnection* connection,
               InterfaceRequest<SurfacesService> request) override;
 
   // SurfacesImpl::Client implementation.
   void OnVSyncParametersUpdated(base::TimeTicks timebase,
                                 base::TimeDelta interval) override;
   void FrameSubmitted() override;
   void SetDisplay(cc::Display*) override;
   void OnDisplayBeingDestroyed(cc::Display* display) override;
 
  private:
   base::TimeDelta tick_interval_;
   cc::SurfaceManager manager_;
   uint32_t next_id_namespace_;
   cc::Display* display_;
   // TODO(jamesr): Integrate with real scheduler.
   base::Timer draw_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(SurfacesServiceApplication);
 };
 
 }  // namespace mojo
 
 #endif  //  MOJO_SERVICES_SURFACES_SURFACES_SERVICE_APPLICATION_H_