Migrate ArcService to BrowserContextKeyedService part 11.

This CL migrates ArcMetricsService.

BUG=672829
TEST=Ran try.

Change-Id: If61b381d0aac425117601b0f514aaebac431e9bc
Reviewed-on: https://chromium-review.googlesource.com/572471
Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
Reviewed-by: Yusuke Sato (in China Mon-Thurs, may be offline) <yusukes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487011}

chrome/browser/chromeos/arc/arc_service_launcher.cc

@@ -100,8 +100,6 @@ void ArcServiceLauncher::Initialize() {
       base::MakeUnique<ArcImeService>(arc_bridge_service));
   arc_service_manager_->AddService(
       base::MakeUnique<ArcIntentHelperBridge>(arc_bridge_service));
-  arc_service_manager_->AddService(
-      base::MakeUnique<ArcMetricsService>(arc_bridge_service));
   arc_service_manager_->AddService(
       base::MakeUnique<ArcNetHostImpl>(arc_bridge_service));
   arc_service_manager_->AddService(
@@ -195,6 +193,7 @@ void ArcServiceLauncher::OnPrimaryUserProfilePrepared(Profile* profile) {
   ArcCrashCollectorBridge::GetForBrowserContext(profile);
   ArcEnterpriseReportingService::GetForBrowserContext(profile);
   ArcFileSystemMounter::GetForBrowserContext(profile);
+  ArcMetricsService::GetForBrowserContext(profile);
 
   arc_service_manager_->AddService(base::MakeUnique<ArcBootPhaseMonitorBridge>(
       arc_service_manager_->arc_bridge_service(),

components/arc/metrics/arc_metrics_service.cc

@@ -8,12 +8,14 @@
 #include <utility>
 
 #include "base/logging.h"
+#include "base/memory/singleton.h"
 #include "base/metrics/histogram_functions.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/string_util.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "components/arc/arc_bridge_service.h"
+#include "components/arc/arc_browser_context_keyed_service_factory_base.h"
 
 namespace arc {
 
@@ -44,21 +46,54 @@ std::string BootTypeToString(mojom::BootType boot_type) {
   return "";
 }
 
+// Singleton factory for ArcMetricsService.
+class ArcMetricsServiceFactory
+    : public internal::ArcBrowserContextKeyedServiceFactoryBase<
+          ArcMetricsService,
+          ArcMetricsServiceFactory> {
+ public:
+  // Factory name used by ArcBrowserContextKeyedServiceFactoryBase.
+  static constexpr const char* kName = "ArcMetricsServiceFactory";
+
+  static ArcMetricsServiceFactory* GetInstance() {
+    return base::Singleton<ArcMetricsServiceFactory>::get();
+  }
+
+ private:
+  friend base::DefaultSingletonTraits<ArcMetricsServiceFactory>;
+  ArcMetricsServiceFactory() = default;
+  ~ArcMetricsServiceFactory() override = default;
+};
+
 }  // namespace
 
-ArcMetricsService::ArcMetricsService(ArcBridgeService* bridge_service)
-    : ArcService(bridge_service),
+// static
+ArcMetricsService* ArcMetricsService::GetForBrowserContext(
+    content::BrowserContext* context) {
+  return ArcMetricsServiceFactory::GetForBrowserContext(context);
+}
+
+ArcMetricsService::ArcMetricsService(content::BrowserContext* context,
+                                     ArcBridgeService* bridge_service)
+    : arc_bridge_service_(bridge_service),
       binding_(this),
       process_observer_(this),
       weak_ptr_factory_(this) {
-  arc_bridge_service()->metrics()->AddObserver(this);
-  arc_bridge_service()->process()->AddObserver(&process_observer_);
+  arc_bridge_service_->metrics()->AddObserver(this);
+  arc_bridge_service_->process()->AddObserver(&process_observer_);
 }
 
 ArcMetricsService::~ArcMetricsService() {
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
-  arc_bridge_service()->process()->RemoveObserver(&process_observer_);
-  arc_bridge_service()->metrics()->RemoveObserver(this);
+
+  // TODO(hidehiko): Currently, the lifetime of ArcBridgeService and
+  // BrowserContextKeyedService is not nested.
+  // If ArcServiceManager::Get() returns nullptr, it is already destructed,
+  // so do not touch it.
+  if (ArcServiceManager::Get()) {
+    arc_bridge_service_->process()->RemoveObserver(&process_observer_);
+    arc_bridge_service_->metrics()->RemoveObserver(this);
+  }
 }
 
 void ArcMetricsService::OnInstanceReady() {
@@ -91,7 +126,7 @@ void ArcMetricsService::OnProcessInstanceClosed() {
 
 void ArcMetricsService::RequestProcessList() {
   mojom::ProcessInstance* process_instance = ARC_GET_INSTANCE_FOR_METHOD(
-      arc_bridge_service()->process(), RequestProcessList);
+      arc_bridge_service_->process(), RequestProcessList);
   if (!process_instance)
     return;
   VLOG(2) << "RequestProcessList";
@@ -134,7 +169,7 @@ void ArcMetricsService::OnArcStartTimeRetrieved(
     return;
   }
   auto* instance =
-      ARC_GET_INSTANCE_FOR_METHOD(arc_bridge_service()->metrics(), Init);
+      ARC_GET_INSTANCE_FOR_METHOD(arc_bridge_service_->metrics(), Init);
   if (!instance)
     return;
 

components/arc/metrics/arc_metrics_service.h

@@ -11,23 +11,33 @@
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
 #include "base/timer/timer.h"
-#include "components/arc/arc_service.h"
 #include "components/arc/common/metrics.mojom.h"
 #include "components/arc/common/process.mojom.h"
 #include "components/arc/instance_holder.h"
+#include "components/keyed_service/core/keyed_service.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
+namespace content {
+class BrowserContext;
+}  // namespace content
+
 namespace arc {
 
 class ArcBridgeService;
 
 // Collects information from other ArcServices and send UMA metrics.
 class ArcMetricsService
-    : public ArcService,
+    : public KeyedService,
       public InstanceHolder<mojom::MetricsInstance>::Observer,
       public mojom::MetricsHost {
  public:
-  explicit ArcMetricsService(ArcBridgeService* bridge_service);
+  // Returns singleton instance for the given BrowserContext,
+  // or nullptr if the browser |context| is not allowed to use ARC.
+  static ArcMetricsService* GetForBrowserContext(
+      content::BrowserContext* context);
+
+  ArcMetricsService(content::BrowserContext* context,
+                    ArcBridgeService* bridge_service);
   ~ArcMetricsService() override;
 
   // InstanceHolder<mojom::MetricsInstance>::Observer overrides.
@@ -68,6 +78,8 @@ class ArcMetricsService
 
   THREAD_CHECKER(thread_checker_);
 
+  ArcBridgeService* const arc_bridge_service_;  // Owned by ArcServiceManager.
+
   mojo::Binding<mojom::MetricsHost> binding_;
 
   ProcessObserver process_observer_;