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

sky/viewer/viewer.cc

 // 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.
 
 #include "base/files/file_path.h"
 #include "base/message_loop/message_loop.h"
 #include "base/threading/thread.h"
 #include "mojo/application/application_runner_chromium.h"
 #include "mojo/common/tracing_impl.h"
 #include "mojo/public/c/system/main.h"
 #include "mojo/public/cpp/application/application_connection.h"
 #include "mojo/public/cpp/application/application_delegate.h"
 #include "mojo/public/cpp/application/application_impl.h"
 #include "mojo/public/cpp/application/interface_factory_impl.h"
 #include "mojo/services/public/interfaces/content_handler/content_handler.mojom.h"
 #include "sky/engine/public/web/Sky.h"
 #include "sky/viewer/content_handler_impl.h"
 #include "sky/viewer/document_view.h"
 #include "sky/viewer/platform/platform_impl.h"
 
 #if !defined(COMPONENT_BUILD)
 #include "base/i18n/icu_util.h"
 #endif
 
 namespace sky {
 
 class Viewer : public mojo::ApplicationDelegate,
-               public mojo::InterfaceFactory<mojo::ContentHandler>,
-               public mojo::InterfaceFactory<mojo::Tracing> {
+               public mojo::InterfaceFactory<mojo::ContentHandler> {
  public:
   Viewer() {}
 
   virtual ~Viewer() { blink::shutdown(); }
 
  private:
   // Overridden from ApplicationDelegate:
   virtual void Initialize(mojo::ApplicationImpl* app) override {
     platform_impl_.reset(new PlatformImpl(app));
     blink::initialize(platform_impl_.get());
     base::i18n::InitializeICU();
+
+    mojo::TracingImpl::Create(app);
   }
 
   virtual bool ConfigureIncomingConnection(
       mojo::ApplicationConnection* connection) override {
     connection->AddService<mojo::ContentHandler>(this);
-    connection->AddService<mojo::Tracing>(this);
     return true;
   }
 
   // Overridden from InterfaceFactory<ContentHandler>
   virtual void Create(mojo::ApplicationConnection* connection,
                       mojo::InterfaceRequest<mojo::ContentHandler> request) override {
     mojo::BindToRequest(new ContentHandlerImpl(), &request);
   }
 
-  // Overridden from InterfaceFactory<Tracing>
-  virtual void Create(mojo::ApplicationConnection* connection,
-                      mojo::InterfaceRequest<mojo::Tracing> request) override {
-    new mojo::TracingImpl(request.Pass(), FILE_PATH_LITERAL("sky_viewer"));
-  }
-
   scoped_ptr<PlatformImpl> platform_impl_;
 
   DISALLOW_COPY_AND_ASSIGN(Viewer);
 };
 
 }  // namespace mojo
 
 MojoResult MojoMain(MojoHandle shell_handle) {
   mojo::ApplicationRunnerChromium runner(new sky::Viewer);
   return runner.Run(shell_handle);
 }