Migrate ArcService to BrowserContextKeyedService part 21.

This CL migrates ArcTracingBridge.

BUG=672829
TEST=Ran try.

Change-Id: Ibc52186e24f7e042dfc86541cecf7fc18d2dea50
Reviewed-on: https://chromium-review.googlesource.com/572887Reviewed-by: Yusuke Sato (in China Mon-Thurs, may be offline) <yusukes@chromium.org>
Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487043}

chrome/browser/chromeos/arc/arc_service_launcher.cc

@@ -110,8 +110,6 @@ void ArcServiceLauncher::Initialize() {
       base::MakeUnique<ArcSettingsService>(arc_bridge_service));
   arc_service_manager_->AddService(
       base::MakeUnique<ArcStorageManager>(arc_bridge_service));
-  arc_service_manager_->AddService(
-      base::MakeUnique<ArcTracingBridge>(arc_bridge_service));
   arc_service_manager_->AddService(
       base::MakeUnique<ArcTtsService>(arc_bridge_service));
   arc_service_manager_->AddService(
@@ -190,6 +188,7 @@ void ArcServiceLauncher::OnPrimaryUserProfilePrepared(Profile* profile) {
   ArcPowerBridge::GetForBrowserContext(profile);
   ArcPrintService::GetForBrowserContext(profile);
   ArcProvisionNotificationService::GetForBrowserContext(profile);
+  ArcTracingBridge::GetForBrowserContext(profile);
 
   arc_service_manager_->AddService(base::MakeUnique<ArcBootPhaseMonitorBridge>(
       arc_service_manager_->arc_bridge_service(),

chrome/browser/chromeos/arc/tracing/arc_tracing_bridge.cc

@@ -6,8 +6,10 @@
 
 #include "base/bind.h"
 #include "base/logging.h"
+#include "base/memory/singleton.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/arc/arc_bridge_service.h"
+#include "components/arc/arc_browser_context_keyed_service_factory_base.h"
 #include "components/arc/arc_service_manager.h"
 #include "content/public/browser/browser_thread.h"
 #include "mojo/public/cpp/system/platform_handle.h"
@@ -21,6 +23,25 @@ namespace {
 // the prefix and the real categories.
 constexpr char kCategoryPrefix[] = TRACE_DISABLED_BY_DEFAULT("android ");
 
+// Singleton factory for ArcTracingBridge.
+class ArcTracingBridgeFactory
+    : public internal::ArcBrowserContextKeyedServiceFactoryBase<
+          ArcTracingBridge,
+          ArcTracingBridgeFactory> {
+ public:
+  // Factory name used by ArcBrowserContextKeyedServiceFactoryBase.
+  static constexpr const char* kName = "ArcTracingBridgeFactory";
+
+  static ArcTracingBridgeFactory* GetInstance() {
+    return base::Singleton<ArcTracingBridgeFactory>::get();
+  }
+
+ private:
+  friend base::DefaultSingletonTraits<ArcTracingBridgeFactory>;
+  ArcTracingBridgeFactory() = default;
+  ~ArcTracingBridgeFactory() override = default;
+};
+
 }  // namespace
 
 struct ArcTracingBridge::Category {
@@ -30,21 +51,34 @@ struct ArcTracingBridge::Category {
   std::string full_name;
 };
 
-ArcTracingBridge::ArcTracingBridge(ArcBridgeService* bridge_service)
-    : ArcService(bridge_service), weak_ptr_factory_(this) {
-  arc_bridge_service()->tracing()->AddObserver(this);
+// static
+ArcTracingBridge* ArcTracingBridge::GetForBrowserContext(
+    content::BrowserContext* context) {
+  return ArcTracingBridgeFactory::GetForBrowserContext(context);
+}
+
+ArcTracingBridge::ArcTracingBridge(content::BrowserContext* context,
+                                   ArcBridgeService* bridge_service)
+    : arc_bridge_service_(bridge_service), weak_ptr_factory_(this) {
+  arc_bridge_service_->tracing()->AddObserver(this);
   content::ArcTracingAgent::GetInstance()->SetDelegate(this);
 }
 
 ArcTracingBridge::~ArcTracingBridge() {
   content::ArcTracingAgent::GetInstance()->SetDelegate(nullptr);
-  arc_bridge_service()->tracing()->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_->tracing()->RemoveObserver(this);
 }
 
 void ArcTracingBridge::OnInstanceReady() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   mojom::TracingInstance* tracing_instance = ARC_GET_INSTANCE_FOR_METHOD(
-      arc_bridge_service()->tracing(), QueryAvailableCategories);
+      arc_bridge_service_->tracing(), QueryAvailableCategories);
   if (!tracing_instance)
     return;
   tracing_instance->QueryAvailableCategories(base::Bind(
@@ -73,8 +107,8 @@ void ArcTracingBridge::StartTracing(
     const StartTracingCallback& callback) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
-  mojom::TracingInstance* tracing_instance = ARC_GET_INSTANCE_FOR_METHOD(
-      arc_bridge_service()->tracing(), StartTracing);
+  mojom::TracingInstance* tracing_instance =
+      ARC_GET_INSTANCE_FOR_METHOD(arc_bridge_service_->tracing(), StartTracing);
   if (!tracing_instance) {
     // Use PostTask as the convention of TracingAgent. The caller expects
     // callback to be called after this function returns.
@@ -98,7 +132,7 @@ void ArcTracingBridge::StopTracing(const StopTracingCallback& callback) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   mojom::TracingInstance* tracing_instance =
-      ARC_GET_INSTANCE_FOR_METHOD(arc_bridge_service()->tracing(), StopTracing);
+      ARC_GET_INSTANCE_FOR_METHOD(arc_bridge_service_->tracing(), StopTracing);
   if (!tracing_instance) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE, base::BindOnce(callback, false));

chrome/browser/chromeos/arc/tracing/arc_tracing_bridge.h

@@ -12,22 +12,32 @@
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/trace_event/trace_event.h"
-#include "components/arc/arc_service.h"
 #include "components/arc/common/tracing.mojom.h"
 #include "components/arc/instance_holder.h"
+#include "components/keyed_service/core/keyed_service.h"
 #include "content/public/browser/arc_tracing_agent.h"
 
+namespace content {
+class BrowserContext;
+}  // namespace content
+
 namespace arc {
 
 class ArcBridgeService;
 
 // This class provides the interface to trigger tracing in the container.
 class ArcTracingBridge
-    : public ArcService,
+    : public KeyedService,
       public content::ArcTracingAgent::Delegate,
       public InstanceHolder<mojom::TracingInstance>::Observer {
  public:
-  explicit ArcTracingBridge(ArcBridgeService* bridge_service);
+  // Returns singleton instance for the given BrowserContext,
+  // or nullptr if the browser |context| is not allowed to use ARC.
+  static ArcTracingBridge* GetForBrowserContext(
+      content::BrowserContext* context);
+
+  ArcTracingBridge(content::BrowserContext* context,
+                   ArcBridgeService* bridge_service);
   ~ArcTracingBridge() override;
 
   // InstanceHolder<mojom::TracingInstance>::Observer overrides:
@@ -45,6 +55,8 @@ class ArcTracingBridge
   // Callback for QueryAvailableCategories.
   void OnCategoriesReady(const std::vector<std::string>& categories);
 
+  ArcBridgeService* const arc_bridge_service_;  // Owned by ArcServiceManager.
+
   // List of available categories.
   std::vector<Category> categories_;