Implement getting notifications up to the browser process.

content/child/notifications/notification_dispatcher.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 "content/child/notifications/notification_dispatcher.h"
 
+#include <limits>
+
 #include "content/child/notifications/notification_manager.h"
-#include "content/common/platform_notification_messages.h"
 
 namespace content {
 
 NotificationDispatcher::NotificationDispatcher(
     ThreadSafeSender* thread_safe_sender)
-    : WorkerThreadMessageFilter(thread_safe_sender), next_notification_id_(0) {
+    : WorkerThreadMessageFilter(thread_safe_sender) {
 }
 
 NotificationDispatcher::~NotificationDispatcher() {}
 
 int NotificationDispatcher::GenerateNotificationId(int thread_id) {
   base::AutoLock lock(notification_id_map_lock_);
+  CHECK_LT(next_notification_id_, std::numeric_limits<int>::max());
+
   notification_id_map_[next_notification_id_] = thread_id;
   return next_notification_id_++;
 }
 
 bool NotificationDispatcher::ShouldHandleMessage(
     const IPC::Message& msg) const {
   return IPC_MESSAGE_CLASS(msg) == PlatformNotificationMsgStart;
 }
 
 void NotificationDispatcher::OnFilteredMessageReceived(
@@ skipping 13 matching lines @@
   base::AutoLock lock(notification_id_map_lock_);
   auto iterator = notification_id_map_.find(notification_id);
   if (iterator != notification_id_map_.end()) {
     *ipc_thread_id = iterator->second;
     return true;
   }
   return false;
 }
 
 }  // namespace content