[GCM] Observe the event listener adding such that GCM can be started

BUG=349578
TEST=Manual test by following repro steps
R=fgorski@chromium.org

Review URL: https://codereview.chromium.org/189803002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255729 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/extensions/api/gcm/gcm_api.cc

@@ -15,7 +15,6 @@
 #include "chrome/browser/services/gcm/gcm_profile_service.h"
 #include "chrome/browser/services/gcm/gcm_profile_service_factory.h"
 #include "chrome/common/extensions/api/gcm.h"
-#include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_system.h"
 #include "extensions/common/extension.h"
 
@@ -179,9 +178,21 @@ bool GcmSendFunction::ValidateMessageData(
   return total_size != 0;
 }
 
-GcmJsEventRouter::GcmJsEventRouter(Profile* profile) : profile_(profile) {}
+GcmJsEventRouter::GcmJsEventRouter(Profile* profile) : profile_(profile) {
+  if (ExtensionSystem::Get(profile_)->event_router()) {
+    ExtensionSystem::Get(profile_)->event_router()->RegisterObserver(
+        this, api::gcm::OnMessage::kEventName);
+    ExtensionSystem::Get(profile_)->event_router()->RegisterObserver(
+        this, api::gcm::OnMessagesDeleted::kEventName);
+    ExtensionSystem::Get(profile_)->event_router()->RegisterObserver(
+        this, api::gcm::OnSendError::kEventName);
+  }
+}
 
-GcmJsEventRouter::~GcmJsEventRouter() {}
+GcmJsEventRouter::~GcmJsEventRouter() {
+  if (ExtensionSystem::Get(profile_)->event_router())
+    ExtensionSystem::Get(profile_)->event_router()->UnregisterObserver(this);
+}
 
 void GcmJsEventRouter::OnMessage(
     const std::string& app_id,
@@ -223,4 +234,12 @@ void GcmJsEventRouter::OnSendError(const std::string& app_id,
       app_id, event.Pass());
 }
 
+void GcmJsEventRouter::OnListenerAdded(const EventListenerInfo& details) {
+  if (gcm::GCMProfileService::GetGCMEnabledState(profile_) ==
+      gcm::GCMProfileService::ALWAYS_DISABLED) {
+    return;
+  }
+  gcm::GCMProfileServiceFactory::GetForProfile(profile_)->Start();
+}
+
 }  // namespace extensions

chrome/browser/extensions/api/gcm/gcm_api.h

@@ -7,6 +7,7 @@
 
 #include "chrome/browser/services/gcm/gcm_event_router.h"
 #include "chrome/common/extensions/api/gcm.h"
+#include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_function.h"
 #include "google_apis/gcm/gcm_client.h"
 
@@ -75,7 +76,8 @@ class GcmSendFunction : public GcmApiFunction {
   bool ValidateMessageData(const gcm::GCMClient::MessageData& data) const;
 };
 
-class GcmJsEventRouter : public gcm::GCMEventRouter {
+class GcmJsEventRouter : public gcm::GCMEventRouter,
+                         public EventRouter::Observer {
  public:
   explicit GcmJsEventRouter(Profile* profile);
 
@@ -90,6 +92,9 @@ class GcmJsEventRouter : public gcm::GCMEventRouter {
                            const std::string& message_id,
                            gcm::GCMClient::Result result) OVERRIDE;
 
+  // EventRouter::Observer:
+  virtual void OnListenerAdded(const EventListenerInfo& details) OVERRIDE;
+
  private:
   // The application we route the event to is running in context of the
   // |profile_| and the latter outlives the event router.

chrome/browser/services/gcm/gcm_profile_service.cc

@@ -569,6 +569,10 @@ void GCMProfileService::Initialize(
                  chrome:: NOTIFICATION_EXTENSION_UNINSTALLED,
                  content::Source<Profile>(profile_));
 
+#if !defined(OS_ANDROID)
+  js_event_router_.reset(new extensions::GcmJsEventRouter(profile_));
+#endif
+
   // Get the list of available accounts.
   std::vector<std::string> account_ids;
 #if !defined(OS_ANDROID)
@@ -618,6 +622,12 @@ void GCMProfileService::Stop() {
       base::Bind(&GCMProfileService::IOWorker::Stop, io_worker_));
 }
 
+void GCMProfileService::Shutdown() {
+#if !defined(OS_ANDROID)
+  js_event_router_.reset();
+#endif
+}
+
 void GCMProfileService::Register(const std::string& app_id,
                                  const std::vector<std::string>& sender_ids,
                                  RegisterCallback callback) {
@@ -825,11 +835,6 @@ void GCMProfileService::EnsureLoaded() {
     return;
   username_ = username;
 
-#if !defined(OS_ANDROID)
-  if (!js_event_router_)
-    js_event_router_.reset(new extensions::GcmJsEventRouter(profile_));
-#endif
-
   DCHECK(!delayed_task_controller_);
   delayed_task_controller_.reset(new DelayedTaskController);
 

chrome/browser/services/gcm/gcm_profile_service.h

@@ -86,6 +86,9 @@ class GCMProfileService : public BrowserContextKeyedService,
 
   void Stop();
 
+  // BrowserContextKeyedService implementation.
+  virtual void Shutdown() OVERRIDE;
+
   // Registers |sender_id| for an app. A registration ID will be returned by
   // the GCM server.
   // |app_id|: application ID.

chrome/browser/services/gcm/gcm_profile_service_unittest.cc

@@ -30,6 +30,8 @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/test/test_browser_thread_bundle.h"
+#include "extensions/browser/event_router.h"
+#include "extensions/browser/extension_prefs.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/manifest_constants.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -294,6 +296,12 @@ class GCMProfileServiceTestConsumer : public GCMProfileService::TestingDelegate{
         CommandLine::ForCurrentProcess(), base::FilePath(), false);
     extension_service_ = extension_system->Get(profile())->extension_service();
 
+    // EventRouter is needed for GcmJsEventRouter.
+    if (!extension_system->event_router()) {
+      extension_system->SetEventRouter(scoped_ptr<EventRouter>(
+          new EventRouter(profile(), ExtensionPrefs::Get(profile()))));
+    }
+
     // Enable GCM such that tests could be run on all channels.
     profile()->GetPrefs()->SetBoolean(prefs::kGCMChannelEnabled, true);