Linux native notifications: Add initial unit test

chrome/browser/notifications/notification_platform_bridge_linux.h

Index: chrome/browser/notifications/notification_platform_bridge_linux.h
diff --git a/chrome/browser/notifications/notification_platform_bridge_linux.h b/chrome/browser/notifications/notification_platform_bridge_linux.h
index b824ff7c3e7314db2a2b78e7d19a61db48280a01..89114dc63030a9bcfe4a1b6d6e9d0a7417ac3892 100644
--- a/chrome/browser/notifications/notification_platform_bridge_linux.h
+++ b/chrome/browser/notifications/notification_platform_bridge_linux.h
@@ -12,6 +12,14 @@
 
 class NotificationPlatformBridgeLinuxImpl;
 
+namespace base {
+class SequencedTaskRunner;
+}
+
+namespace dbus {
+class Bus;
+}
+
 class NotificationPlatformBridgeLinux : public NotificationPlatformBridge {
  public:
   NotificationPlatformBridgeLinux();
@@ -33,6 +41,15 @@ class NotificationPlatformBridgeLinux : public NotificationPlatformBridge {
   void SetReadyCallback(NotificationBridgeReadyCallback callback) override;
 
  private:
+  friend class NotificationPlatformBridgeLinuxTest;
+
+  NotificationPlatformBridgeLinux(

[Lei Zhang, 2017/04/29 01:35:05]

This is for testing only, right? Add a comment?

[Tom (Use chromium acct), 2017/05/01 18:25:29]

Done.

+      scoped_refptr<base::SequencedTaskRunner> notification_task_runner,
+      scoped_refptr<base::SequencedTaskRunner> ui_task_runner,
+      scoped_refptr<dbus::Bus> bus);
+
+  void CleanUp();
+
   scoped_refptr<NotificationPlatformBridgeLinuxImpl> impl_;
 
   DISALLOW_COPY_AND_ASSIGN(NotificationPlatformBridgeLinux);