Remove explicit singletonness of ArcBridgeService part 3.

components/arc/arc_service_manager.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 "components/arc/arc_service_manager.h"
 
 #include <utility>
 
 #include "base/memory/ptr_util.h"
 #include "base/sequenced_task_runner.h"
@@ skipping 33 matching lines @@
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(g_arc_service_manager == this);
   g_arc_service_manager = nullptr;
   if (g_arc_bridge_service_for_testing) {
     delete g_arc_bridge_service_for_testing;
   }
 }
 
 // static
 ArcServiceManager* ArcServiceManager::Get() {
-  DCHECK(g_arc_service_manager);
+  if (!g_arc_service_manager)
+    return nullptr;
   DCHECK(g_arc_service_manager->thread_checker_.CalledOnValidThread());
   return g_arc_service_manager;
 }
 
 // static
 bool ArcServiceManager::IsInitialized() {
   if (!g_arc_service_manager)
     return false;
   DCHECK(g_arc_service_manager->thread_checker_.CalledOnValidThread());
   return true;
@@ skipping 35 matching lines @@
 
 // static
 void ArcServiceManager::SetArcBridgeServiceForTesting(
     std::unique_ptr<ArcBridgeService> arc_bridge_service) {
   if (g_arc_bridge_service_for_testing)
     delete g_arc_bridge_service_for_testing;
   g_arc_bridge_service_for_testing = arc_bridge_service.release();
 }
 
 }  // namespace arc