Linux native notifications: Add initial unit test

chrome/browser/notifications/notification_platform_bridge_linux.cc

Index: chrome/browser/notifications/notification_platform_bridge_linux.cc
diff --git a/chrome/browser/notifications/notification_platform_bridge_linux.cc b/chrome/browser/notifications/notification_platform_bridge_linux.cc
index cf71db8869d0a8a1c7c5f89085a7fd8338243d6c..bd4c1764014d64fb7b4b4423adbe149acfa40e28 100644
--- a/chrome/browser/notifications/notification_platform_bridge_linux.cc
+++ b/chrome/browser/notifications/notification_platform_bridge_linux.cc
@@ -88,7 +88,6 @@ void ForwardNotificationOperationOnUiThread(
     int action_index,
     const std::string& profile_id,
     bool is_incognito) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   ProfileManager* profile_manager = g_browser_process->profile_manager();
 
   profile_manager->LoadProfile(
@@ -127,12 +126,29 @@ class NotificationPlatformBridgeLinuxImpl
       public content::NotificationObserver,
       public base::RefCountedThreadSafe<NotificationPlatformBridgeLinuxImpl> {
  public:
-  NotificationPlatformBridgeLinuxImpl()
-      : task_runner_(base::CreateSingleThreadTaskRunnerWithTraits(
-            base::TaskTraits().MayBlock().WithPriority(
-                base::TaskPriority::USER_BLOCKING))) {
+  NotificationPlatformBridgeLinuxImpl(
+      scoped_refptr<base::SequencedTaskRunner> notification_task_runner,
+      scoped_refptr<base::SequencedTaskRunner> ui_task_runner,
+      scoped_refptr<dbus::Bus> bus)
+      : notification_task_runner_(notification_task_runner),
+        ui_task_runner_(ui_task_runner),
+        bus_(bus) {
+    if (!notification_task_runner_) {
+      notification_task_runner_ = base::CreateSingleThreadTaskRunnerWithTraits(
+          base::TaskTraits().MayBlock().WithPriority(
+              base::TaskPriority::USER_BLOCKING));
+    }
+    DCHECK(ui_task_runner_);
     registrar_.Add(this, chrome::NOTIFICATION_APP_TERMINATING,
                    content::NotificationService::AllSources());
+  }
+
+  // Init() cannot be called from within the constructor because of a
+  // race condition.  The reference count for |this| starts out as 0.
+  // Posting the Init task would increment the count to 1.  If the
+  // task finishes before the constructor returns, the count will go
+  // to 0 and the object would be prematurely destructed.
+  void InitAfterConstructor() {
     PostTaskToTaskRunnerThread(
         base::BindOnce(&NotificationPlatformBridgeLinuxImpl::Init, this));
   }
@@ -142,7 +158,7 @@ class NotificationPlatformBridgeLinuxImpl
                const std::string& profile_id,
                bool is_incognito,
                const Notification& notification) override {
-    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+    DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
     // Notifications contain gfx::Image's which have reference counts
     // that are not thread safe.  Because of this, we duplicate the
     // notification and its images.  Wrap the notification in a
@@ -163,7 +179,7 @@ class NotificationPlatformBridgeLinuxImpl
 
   void Close(const std::string& profile_id,
              const std::string& notification_id) override {
-    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+    DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
     PostTaskToTaskRunnerThread(
         base::BindOnce(&NotificationPlatformBridgeLinuxImpl::CloseOnTaskRunner,
                        this, profile_id, notification_id));
@@ -173,14 +189,14 @@ class NotificationPlatformBridgeLinuxImpl
       const std::string& profile_id,
       bool incognito,
       const GetDisplayedNotificationsCallback& callback) const override {
-    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+    DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
     PostTaskToTaskRunnerThread(base::BindOnce(
         &NotificationPlatformBridgeLinuxImpl::GetDisplayedOnTaskRunner, this,
         profile_id, incognito, callback));
   }
 
   void SetReadyCallback(NotificationBridgeReadyCallback callback) override {
-    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+    DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
     if (connected_.has_value()) {
       std::move(callback).Run(connected_.value());
     } else {
@@ -188,6 +204,15 @@ class NotificationPlatformBridgeLinuxImpl
     }
   }
 
+  void CleanUp() {
+    DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
+    if (cleanup_posted_)
+      return;
+    PostTaskToTaskRunnerThread(base::BindOnce(
+        &NotificationPlatformBridgeLinuxImpl::CleanUpOnTaskRunner, this));
+    cleanup_posted_ = true;
+  }
+
  private:
   friend class base::RefCountedThreadSafe<NotificationPlatformBridgeLinuxImpl>;
 
@@ -238,14 +263,16 @@ class NotificationPlatformBridgeLinuxImpl
   };
 
   ~NotificationPlatformBridgeLinuxImpl() override {
+    DCHECK(cleanup_posted_);
     DCHECK(!bus_);
+    DCHECK(!notification_proxy_);
     DCHECK(notifications_.empty());
   }
 
   void Observe(int type,
                const content::NotificationSource& source,
                const content::NotificationDetails& details) override {
-    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+    DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
     DCHECK_EQ(chrome::NOTIFICATION_APP_TERMINATING, type);
     // The browser process is about to exit.  Post the CleanUp() task
     // while we still can.
@@ -253,27 +280,30 @@ class NotificationPlatformBridgeLinuxImpl
   }
 
   void PostTaskToUiThread(base::OnceClosure closure) const {
-    DCHECK(task_runner_->RunsTasksOnCurrentThread());
-    bool success = content::BrowserThread::PostTask(
-        content::BrowserThread::UI, FROM_HERE, std::move(closure));
+    DCHECK(notification_task_runner_->RunsTasksOnCurrentThread());
+    DCHECK(ui_task_runner_);
+    bool success = ui_task_runner_->PostTask(FROM_HERE, std::move(closure));
     DCHECK(success);
   }
 
   void PostTaskToTaskRunnerThread(base::OnceClosure closure) const {
-    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-    DCHECK(task_runner_);
-    bool success = task_runner_->PostTask(FROM_HERE, std::move(closure));
+    DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
+    DCHECK(notification_task_runner_);
+    bool success =
+        notification_task_runner_->PostTask(FROM_HERE, std::move(closure));
     DCHECK(success);
   }
 
   // Sets up the D-Bus connection.
   void Init() {
-    DCHECK(task_runner_->RunsTasksOnCurrentThread());
-    dbus::Bus::Options bus_options;
-    bus_options.bus_type = dbus::Bus::SESSION;
-    bus_options.connection_type = dbus::Bus::PRIVATE;
-    bus_options.dbus_task_runner = task_runner_;
-    bus_ = make_scoped_refptr(new dbus::Bus(bus_options));
+    DCHECK(notification_task_runner_->RunsTasksOnCurrentThread());
+    if (!bus_) {
+      dbus::Bus::Options bus_options;
+      bus_options.bus_type = dbus::Bus::SESSION;
+      bus_options.connection_type = dbus::Bus::PRIVATE;
+      bus_options.dbus_task_runner = notification_task_runner_;
+      bus_ = make_scoped_refptr(new dbus::Bus(bus_options));
+    }
 
     notification_proxy_ =
         bus_->GetObjectProxy(kFreedesktopNotificationsName,
@@ -300,17 +330,8 @@ class NotificationPlatformBridgeLinuxImpl
                    this));
   }
 
-  void CleanUp() {
-    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-    if (cleanup_posted_)
-      return;
-    PostTaskToTaskRunnerThread(base::BindOnce(
-        &NotificationPlatformBridgeLinuxImpl::CleanUpOnTaskRunner, this));
-    cleanup_posted_ = true;
-  }
-
   void CleanUpOnTaskRunner() {
-    DCHECK(task_runner_->RunsTasksOnCurrentThread());
+    DCHECK(notification_task_runner_->RunsTasksOnCurrentThread());
     bus_->ShutdownAndBlock();
     bus_ = nullptr;
     notification_proxy_ = nullptr;
@@ -323,7 +344,7 @@ class NotificationPlatformBridgeLinuxImpl
                            const std::string& profile_id,
                            bool is_incognito,
                            std::unique_ptr<Notification> notification) {
-    DCHECK(task_runner_->RunsTasksOnCurrentThread());
+    DCHECK(notification_task_runner_->RunsTasksOnCurrentThread());
     NotificationData* data =
         FindNotificationData(notification_id, profile_id, is_incognito);
     if (data) {
@@ -431,7 +452,7 @@ class NotificationPlatformBridgeLinuxImpl
   // Makes the "CloseNotification" call to D-Bus.
   void CloseOnTaskRunner(const std::string& profile_id,
                          const std::string& notification_id) {
-    DCHECK(task_runner_->RunsTasksOnCurrentThread());
+    DCHECK(notification_task_runner_->RunsTasksOnCurrentThread());
     std::vector<NotificationData*> to_erase;
     for (const auto& pair : notifications_) {
       NotificationData* data = pair.first;
@@ -453,7 +474,7 @@ class NotificationPlatformBridgeLinuxImpl
       const std::string& profile_id,
       bool incognito,
       const GetDisplayedNotificationsCallback& callback) const {
-    DCHECK(task_runner_->RunsTasksOnCurrentThread());
+    DCHECK(notification_task_runner_->RunsTasksOnCurrentThread());
     // TODO(thomasanderson): Implement.
     PostTaskToUiThread(base::BindOnce(
         callback, base::Passed(base::MakeUnique<std::set<std::string>>()),
@@ -463,7 +484,7 @@ class NotificationPlatformBridgeLinuxImpl
   NotificationData* FindNotificationData(const std::string& notification_id,
                                          const std::string& profile_id,
                                          bool is_incognito) {
-    DCHECK(task_runner_->RunsTasksOnCurrentThread());
+    DCHECK(notification_task_runner_->RunsTasksOnCurrentThread());
     for (const auto& pair : notifications_) {
       NotificationData* data = pair.first;
       if (data->notification_id == notification_id &&
@@ -477,7 +498,7 @@ class NotificationPlatformBridgeLinuxImpl
   }
 
   NotificationData* FindNotificationData(uint32_t dbus_id) {
-    DCHECK(task_runner_->RunsTasksOnCurrentThread());
+    DCHECK(notification_task_runner_->RunsTasksOnCurrentThread());
     for (const auto& pair : notifications_) {
       NotificationData* data = pair.first;
       if (data->dbus_id == dbus_id)
@@ -490,7 +511,7 @@ class NotificationPlatformBridgeLinuxImpl
   void ForwardNotificationOperation(NotificationData* data,
                                     NotificationCommon::Operation operation,
                                     int action_index) {
-    DCHECK(task_runner_->RunsTasksOnCurrentThread());
+    DCHECK(notification_task_runner_->RunsTasksOnCurrentThread());
     PostTaskToUiThread(base::BindOnce(
         ForwardNotificationOperationOnUiThread, operation,
         data->notification_type, data->origin_url.spec(), data->notification_id,
@@ -498,7 +519,7 @@ class NotificationPlatformBridgeLinuxImpl
   }
 
   void OnActionInvoked(dbus::Signal* signal) {
-    DCHECK(task_runner_->RunsTasksOnCurrentThread());
+    DCHECK(notification_task_runner_->RunsTasksOnCurrentThread());
     dbus::MessageReader reader(signal);
     uint32_t dbus_id;
     if (!reader.PopUint32(&dbus_id))
@@ -529,7 +550,7 @@ class NotificationPlatformBridgeLinuxImpl
   }
 
   void OnNotificationClosed(dbus::Signal* signal) {
-    DCHECK(task_runner_->RunsTasksOnCurrentThread());
+    DCHECK(notification_task_runner_->RunsTasksOnCurrentThread());
     dbus::MessageReader reader(signal);
     uint32_t dbus_id;
     if (!reader.PopUint32(&dbus_id))
@@ -546,7 +567,7 @@ class NotificationPlatformBridgeLinuxImpl
   // Called once the connection has been set up (or not).  |success|
   // indicates the connection is ready to use.
   void OnConnectionInitializationFinishedOnUiThread(bool success) {
-    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+    DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
     connected_ = success;
     for (auto& callback : on_connected_callbacks_)
       std::move(callback).Run(success);
@@ -556,7 +577,7 @@ class NotificationPlatformBridgeLinuxImpl
   }
 
   void OnConnectionInitializationFinishedOnTaskRunner(bool success) {
-    DCHECK(task_runner_->RunsTasksOnCurrentThread());
+    DCHECK(notification_task_runner_->RunsTasksOnCurrentThread());
     PostTaskToUiThread(
         base::BindOnce(&NotificationPlatformBridgeLinuxImpl::
                            OnConnectionInitializationFinishedOnUiThread,
@@ -566,7 +587,7 @@ class NotificationPlatformBridgeLinuxImpl
   void OnSignalConnected(const std::string& interface_name,
                          const std::string& signal_name,
                          bool success) {
-    DCHECK(task_runner_->RunsTasksOnCurrentThread());
+    DCHECK(notification_task_runner_->RunsTasksOnCurrentThread());
     if (!success) {
       OnConnectionInitializationFinishedOnTaskRunner(false);
       return;
@@ -577,7 +598,7 @@ class NotificationPlatformBridgeLinuxImpl
   //////////////////////////////////////////////////////////////////////////////
   // Members used only on the UI thread.
 
-  scoped_refptr<base::SequencedTaskRunner> task_runner_;
+  scoped_refptr<base::SequencedTaskRunner> notification_task_runner_;
 
   content::NotificationRegistrar registrar_;
 
@@ -591,6 +612,8 @@ class NotificationPlatformBridgeLinuxImpl
   //////////////////////////////////////////////////////////////////////////////
   // Members used only on the task runner thread.
 
+  scoped_refptr<base::SequencedTaskRunner> ui_task_runner_;
+
   scoped_refptr<dbus::Bus> bus_;
 
   dbus::ObjectProxy* notification_proxy_ = nullptr;
@@ -609,7 +632,23 @@ class NotificationPlatformBridgeLinuxImpl
 };
 
 NotificationPlatformBridgeLinux::NotificationPlatformBridgeLinux()
-    : impl_(new NotificationPlatformBridgeLinuxImpl()) {}
+    : NotificationPlatformBridgeLinux(
+          nullptr,
+          content::BrowserThread::GetTaskRunnerForThread(
+              content::BrowserThread::UI),
+          nullptr) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+}
+
+NotificationPlatformBridgeLinux::NotificationPlatformBridgeLinux(
+    scoped_refptr<base::SequencedTaskRunner> notification_task_runner,
+    scoped_refptr<base::SequencedTaskRunner> ui_task_runner,
+    scoped_refptr<dbus::Bus> bus)
+    : impl_(new NotificationPlatformBridgeLinuxImpl(notification_task_runner,
+                                                    ui_task_runner,
+                                                    bus)) {
+  impl_->InitAfterConstructor();
+}
 
 NotificationPlatformBridgeLinux::~NotificationPlatformBridgeLinux() = default;
 
@@ -640,3 +679,7 @@ void NotificationPlatformBridgeLinux::SetReadyCallback(
     NotificationBridgeReadyCallback callback) {
   impl_->SetReadyCallback(std::move(callback));
 }
+
+void NotificationPlatformBridgeLinux::CleanUp() {
+  impl_->CleanUp();
+}