Make TracingImpl take a Shell* and args, instead of an ApplicationImpl*.

services/dart/dart_tracing.cc

 // 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.
 
 #include "services/dart/dart_tracing.h"
 
 #include <utility>
 
 #include "dart/runtime/include/dart_tools_api.h"
 #include "mojo/public/cpp/application/application_impl.h"
@@ skipping 115 matching lines @@
   }
   recorder_.reset();
 }
 
 DartTracingImpl::DartTracingImpl() {
 }
 
 DartTracingImpl::~DartTracingImpl() {
 }
 
-void DartTracingImpl::Initialize(mojo::ApplicationImpl* app) {
+void DartTracingImpl::Initialize(mojo::Shell* shell) {
   tracing::TraceProviderRegistryPtr registry;
-  ConnectToService(app->shell(), "mojo:tracing", GetProxy(&registry));
+  ConnectToService(shell, "mojo:tracing", GetProxy(&registry));
 
   mojo::InterfaceHandle<tracing::TraceProvider> provider;
   provider_impl_.Bind(GetProxy(&provider));
   registry->RegisterTraceProvider(provider.Pass());
 }
 
 }  // namespace dart