Push API: test that default notification is shown on Android when needed.

chrome/browser/push_messaging/push_messaging_service_observer_android.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_PUSH_MESSAGING_PUSH_MESSAGING_SERVICE_OBSERVER_ANDROID_H_
+#define CHROME_BROWSER_PUSH_MESSAGING_PUSH_MESSAGING_SERVICE_OBSERVER_ANDROID_H_
+
+#include "chrome/browser/push_messaging/push_messaging_service_observer.h"
+
+#include <jni.h>
+
+#include "base/macros.h"
+
+// Observer for the PushMessagingService to be used on Android for forwarding
+// message handled events to listeners in Java.
+class PushMessagingServiceObserverAndroid
+    : public PushMessagingServiceObserver {
+ public:
+  static bool RegisterJni(JNIEnv* env);
+
+  // PushMessagingServiceObserver implementation.
+  void OnMessageHandled() override;
+
+ private:
+  friend class PushMessagingServiceObserver;

[Bernhard Bauer, 2015/12/11 12:28:42]

You could add a protected empty constructor to the base class, then you don't
need to friend it here.

[Michael van Ouwerkerk, 2015/12/11 16:05:56]

I'm not sure what you meant by this actually. How does that allow
PushMessagingServiceObserver::Create to call
PushMessagingServiceObserverAndroid?

+  PushMessagingServiceObserverAndroid() {}
+
+  DISALLOW_COPY_AND_ASSIGN(PushMessagingServiceObserverAndroid);
+};
+
+#endif  // CHROME_BROWSER_PUSH_MESSAGING_PUSH_MESSAGING_SERVICE_OBSERVER_ANDROID_H_