Make tracing work in service manager

services/service_manager/service_manager.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 "services/service_manager/service_manager.h"
 
 #include <stdint.h>
 
 #include <utility>
 
@@ skipping 488 matching lines @@
     : native_runner_factory_(std::move(native_runner_factory)),
       weak_ptr_factory_(this) {
   mojom::ServicePtr service;
   mojom::ServiceRequest request = mojo::GetProxy(&service);
 
   InterfaceProviderSpec spec;
   spec.provides[kCapability_ServiceManager].insert(
       "service_manager::mojom::ServiceManager");
   spec.requires["*"].insert("service_manager:service_factory");
   spec.requires["service:catalog"].insert("service_manager:resolver");
+  spec.requires["service:tracing"].insert("app");
 
   service_manager_instance_ =
       CreateInstance(Identity(), CreateServiceManagerIdentity(), spec);
   service_manager_instance_->StartWithService(std::move(service));
   singletons_.insert(kServiceManagerName);
   service_context_.reset(new ServiceContext(this, std::move(request)));
 
   if (catalog)
     InitCatalog(std::move(catalog));
 }
@@ skipping 362 matching lines @@
   // Now that the instance has a Service, we can connect to it.
   bool connected = instance->ConnectToService(&params);
   DCHECK(connected);
 }
 
 base::WeakPtr<ServiceManager> ServiceManager::GetWeakPtr() {
   return weak_ptr_factory_.GetWeakPtr();
 }
 
 }  // namespace service_manager