Remove explicit singletonness of ArcBridgeService part 5.

Remove ArcBridgeService::Get().
Now all usage was gone. It's time to delete the function.

BUG=657687
BUG=b/31079732
TEST=Ran bots.

Review-Url: https://codereview.chromium.org/2558313002
Cr-Commit-Position: refs/heads/master@{#437816}

components/arc/arc_bridge_service.cc

@@ -21,9 +21,6 @@ const base::Feature kArcEnabledFeature{"EnableARC",
 
 }  // namespace
 
-// Weak pointer.  This class is owned by ArcServiceManager.
-ArcBridgeService* g_arc_bridge_service = nullptr;
-
 ArcBridgeService::ArcBridgeService()
     : state_(State::STOPPED),
       stop_reason_(StopReason::SHUTDOWN),
@@ -34,18 +31,6 @@ ArcBridgeService::~ArcBridgeService() {
   DCHECK(state() == State::STOPPING || state() == State::STOPPED);
 }
 
-// static
-ArcBridgeService* ArcBridgeService::Get() {
-  if (!g_arc_bridge_service) {
-    // ArcBridgeService may be indirectly referenced in unit tests where
-    // ArcBridgeService is optional.
-    LOG(ERROR) << "ArcBridgeService is not ready.";
-    return nullptr;
-  }
-  DCHECK(g_arc_bridge_service->CalledOnValidThread());
-  return g_arc_bridge_service;
-}
-
 // static
 bool ArcBridgeService::GetEnabled(const base::CommandLine* command_line) {
   return command_line->HasSwitch(chromeos::switches::kEnableArc) ||

components/arc/arc_bridge_service.h

@@ -90,10 +90,6 @@ class ArcBridgeService {
 
   virtual ~ArcBridgeService();
 
-  // Gets the global instance of the ARC Bridge Service. This can only be
-  // called on the thread that this class was created on.
-  static ArcBridgeService* Get();
-
   // Return true if ARC has been enabled through a commandline
   // switch.
   static bool GetEnabled(const base::CommandLine* command_line);

components/arc/arc_bridge_service_impl.cc

@@ -21,9 +21,6 @@
 #include "components/prefs/pref_service.h"
 
 namespace arc {
-
-extern ArcBridgeService* g_arc_bridge_service;
-
 namespace {
 constexpr int64_t kReconnectDelayInSeconds = 5;
 }  // namespace
@@ -32,17 +29,11 @@ ArcBridgeServiceImpl::ArcBridgeServiceImpl(
     const scoped_refptr<base::TaskRunner>& blocking_task_runner)
     : session_started_(false),
       factory_(base::Bind(ArcSession::Create, this, blocking_task_runner)),
-      weak_factory_(this) {
-  DCHECK(!g_arc_bridge_service);
-  g_arc_bridge_service = this;
-}
+      weak_factory_(this) {}
 
 ArcBridgeServiceImpl::~ArcBridgeServiceImpl() {
   if (arc_session_)
     arc_session_->RemoveObserver(this);
-
-  DCHECK(g_arc_bridge_service == this);
-  g_arc_bridge_service = nullptr;
 }
 
 void ArcBridgeServiceImpl::RequestStart() {

components/arc/test/fake_arc_bridge_service.cc

@@ -6,16 +6,9 @@
 
 namespace arc {
 
-extern ArcBridgeService* g_arc_bridge_service;
-
-FakeArcBridgeService::FakeArcBridgeService() {
-  DCHECK(!g_arc_bridge_service);
-  g_arc_bridge_service = this;
-}
+FakeArcBridgeService::FakeArcBridgeService() = default;
 
 FakeArcBridgeService::~FakeArcBridgeService() {
-  DCHECK(g_arc_bridge_service == this);
-  g_arc_bridge_service = nullptr;
   SetStopped();
 }