Implement the Notification `timestamp` property

chrome/browser/notifications/notification_ui_manager_android.cc

 // Copyright 2014 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.
 
 #include "chrome/browser/notifications/notification_ui_manager_android.h"
 
 #include <utility>
 
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
@@ skipping 134 matching lines @@
   Java_NotificationUIManager_displayNotification(
       env,
       java_object_.obj(),
       persistent_notification_id,
       origin.obj(),
       tag.obj(),
       title.obj(),
       body.obj(),
       icon.obj(),
       vibration_pattern.obj(),
+      notification.timestamp().ToJavaTime(),

[johnme, 2015/10/20 17:12:21]

FYI ToJavaTime can underflow for times in between 1601 and 1970, but I think
you're ok here since your base::Time is after 1970.

[Peter Beverloo, 2016/01/28 17:18:29]

Acknowledged.

       notification.silent(),
       action_titles.obj());
 
   regenerated_notification_infos_[persistent_notification_id] =
       std::make_pair(origin_url.spec(), notification.tag());
 
   notification.delegate()->Display();
 }
 
 bool NotificationUIManagerAndroid::Update(const Notification& notification,
@@ skipping 67 matching lines @@
   return false;
 }
 
 void NotificationUIManagerAndroid::CancelAll() {
   NOTREACHED();
 }
 
 bool NotificationUIManagerAndroid::RegisterNotificationUIManager(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }