Use TraceProviderRegistry in //mojo/common/tracing_impl.*.

services/tracing/tracing_app.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/tracing/tracing_app.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "mojo/public/cpp/system/wait.h"
 
 namespace tracing {
 
 TracingApp::TracingApp() : collector_binding_(this), tracing_active_(false) {}
 
 TracingApp::~TracingApp() {}
 
 bool TracingApp::ConfigureIncomingConnection(
     mojo::ApplicationConnection* connection) {
   connection->AddService<TraceCollector>(this);
 
   // If someone connects to us they may want to use the TraceCollector
   // interface and/or they may want to expose themselves to be traced. Attempt
   // to connect to the TraceProvider interface to see if the application
   // connecting to us wants to be traced. They can refuse the connection or
   // close the pipe if not.
   // TODO(vtl): Remove this once we remove the "wrong way" ServiceProvider.
   TraceProviderPtr provider_ptr;
   connection->ConnectToService(&provider_ptr);
-  RegisterTraceProvider(provider_ptr.PassInterfaceHandle());
+  if (provider_ptr)
+    RegisterTraceProvider(provider_ptr.PassInterfaceHandle());
 
   return true;
 }
 
 void TracingApp::Create(mojo::ApplicationConnection* connection,
                         mojo::InterfaceRequest<TraceCollector> request) {
   if (collector_binding_.is_bound()) {
     LOG(ERROR) << "Another application is already connected to tracing.";
     return;
   }
@@ skipping 95 matching lines @@
   }
   provider_ptrs_.AddInterfacePtr(provider_ptr.Pass());
 }
 
 void TracingApp::AllDataCollected() {
   recorder_impls_.clear();
   sink_.reset();
 }
 
 }  // namespace tracing