Migrate ArcService to BrowserContextKeyedService part 16.

This CL migrates ArcPrintService.

BUG=672829
TEST=Ran try.

Change-Id: Ia223ec8dc9d05d044ddb66812cd322d705cb1d39
Reviewed-on: https://chromium-review.googlesource.com/572882
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@{#487017}

chrome/browser/chromeos/arc/arc_service_launcher.cc

@@ -104,8 +104,6 @@ void ArcServiceLauncher::Initialize() {
       base::MakeUnique<ArcNetHostImpl>(arc_bridge_service));
   arc_service_manager_->AddService(
       base::MakeUnique<ArcPolicyBridge>(arc_bridge_service));
-  arc_service_manager_->AddService(
-      base::MakeUnique<ArcPrintService>(arc_bridge_service));
   arc_service_manager_->AddService(
       base::MakeUnique<ArcProcessService>(arc_bridge_service));
   arc_service_manager_->AddService(
@@ -192,6 +190,7 @@ void ArcServiceLauncher::OnPrimaryUserProfilePrepared(Profile* profile) {
   ArcMetricsService::GetForBrowserContext(profile);
   ArcObbMounterBridge::GetForBrowserContext(profile);
   ArcPowerBridge::GetForBrowserContext(profile);
+  ArcPrintService::GetForBrowserContext(profile);
 
   arc_service_manager_->AddService(base::MakeUnique<ArcBootPhaseMonitorBridge>(
       arc_service_manager_->arc_bridge_service(),

chrome/browser/chromeos/arc/print/arc_print_service.cc

@@ -11,10 +11,12 @@
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/logging.h"
+#include "base/memory/singleton.h"
 #include "base/task_scheduler/post_task.h"
 #include "base/task_scheduler/task_traits.h"
 #include "base/threading/thread_restrictions.h"
 #include "components/arc/arc_bridge_service.h"
+#include "components/arc/arc_browser_context_keyed_service_factory_base.h"
 #include "mojo/edk/embedder/embedder.h"
 #include "net/base/filename_util.h"
 #include "url/gurl.h"
@@ -45,19 +47,55 @@ base::Optional<base::FilePath> SavePdf(base::File file) {
 }  // namespace
 
 namespace arc {
+namespace {
+
+// Singleton factory for ArcPrintService.
+class ArcPrintServiceFactory
+    : public internal::ArcBrowserContextKeyedServiceFactoryBase<
+          ArcPrintService,
+          ArcPrintServiceFactory> {
+ public:
+  // Factory name used by ArcBrowserContextKeyedServiceFactoryBase.
+  static constexpr const char* kName = "ArcPrintServiceFactory";
+
+  static ArcPrintServiceFactory* GetInstance() {
+    return base::Singleton<ArcPrintServiceFactory>::get();
+  }
+
+ private:
+  friend base::DefaultSingletonTraits<ArcPrintServiceFactory>;
+  ArcPrintServiceFactory() = default;
+  ~ArcPrintServiceFactory() override = default;
+};
+
+}  // namespace
+
+// static
+ArcPrintService* ArcPrintService::GetForBrowserContext(
+    content::BrowserContext* context) {
+  return ArcPrintServiceFactory::GetForBrowserContext(context);
+}
 
-ArcPrintService::ArcPrintService(ArcBridgeService* bridge_service)
-    : ArcService(bridge_service), binding_(this), weak_ptr_factory_(this) {
-  arc_bridge_service()->print()->AddObserver(this);
+ArcPrintService::ArcPrintService(content::BrowserContext* context,
+                                 ArcBridgeService* bridge_service)
+    : arc_bridge_service_(bridge_service),
+      binding_(this),
+      weak_ptr_factory_(this) {
+  arc_bridge_service_->print()->AddObserver(this);
 }
 
 ArcPrintService::~ArcPrintService() {
-  arc_bridge_service()->print()->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_->print()->RemoveObserver(this);
 }
 
 void ArcPrintService::OnInstanceReady() {
   mojom::PrintInstance* print_instance =
-      ARC_GET_INSTANCE_FOR_METHOD(arc_bridge_service()->print(), Init);
+      ARC_GET_INSTANCE_FOR_METHOD(arc_bridge_service_->print(), Init);
   DCHECK(print_instance);
   mojom::PrintHostPtr host_proxy;
   binding_.Bind(mojo::MakeRequest(&host_proxy));

chrome/browser/chromeos/arc/print/arc_print_service.h

@@ -10,20 +10,30 @@
 #include "base/memory/weak_ptr.h"
 #include "base/optional.h"
 #include "base/threading/thread_checker.h"
-#include "components/arc/arc_service.h"
 #include "components/arc/common/print.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;
 
-class ArcPrintService : public ArcService,
+class ArcPrintService : public KeyedService,
                         public InstanceHolder<mojom::PrintInstance>::Observer,
                         public mojom::PrintHost {
  public:
-  explicit ArcPrintService(ArcBridgeService* bridge_service);
+  // Returns singleton instance for the given BrowserContext,
+  // or nullptr if the browser |context| is not allowed to use ARC.
+  static ArcPrintService* GetForBrowserContext(
+      content::BrowserContext* context);
+
+  ArcPrintService(content::BrowserContext* context,
+                  ArcBridgeService* bridge_service);
   ~ArcPrintService() override;
 
   // InstanceHolder<mojom::PrintInstance>::Observer override:
@@ -38,6 +48,8 @@ class ArcPrintService : public ArcService,
   void OpenPdf(base::Optional<base::FilePath> file_path) const;
 
   THREAD_CHECKER(thread_checker_);
+
+  ArcBridgeService* const arc_bridge_service_;  // Owned by ArcServiceManager.
   mojo::Binding<mojom::PrintHost> binding_;
 
   base::WeakPtrFactory<ArcPrintService> weak_ptr_factory_;