Minimize the delegate dependencies for native extension notifications.

chrome/browser/notifications/native_notification_display_service.cc

 // Copyright 2016 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/native_notification_display_service.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
@@ skipping 42 matching lines @@
 
   notification_bridge->SetReadyCallback(base::BindOnce(
       &NativeNotificationDisplayService::OnNotificationPlatformBridgeReady,
       weak_factory_.GetWeakPtr()));
 
   AddNotificationHandler(NotificationCommon::NON_PERSISTENT,
                          base::MakeUnique<NonPersistentNotificationHandler>());
   AddNotificationHandler(NotificationCommon::PERSISTENT,
                          base::MakeUnique<PersistentNotificationHandler>());
 #if BUILDFLAG(ENABLE_EXTENSIONS)
-  AddNotificationHandler(NotificationCommon::EXTENSION,
-                         base::MakeUnique<ExtensionNotificationHandler>());
+  AddNotificationHandler(
+      NotificationCommon::EXTENSION,
+      base::MakeUnique<extensions::ExtensionNotificationHandler>());

[dewittj, 2017/05/16 22:07:17]

Depending on where else this type is referenced, it might make sense to rename
to just extensions::NotificationHandler (or similar) which is shorter.

[Miguel Garcia, 2017/05/20 07:04:10]

I've noticed this pattern with the notification delegate but I honestly have
found it harder to follow than giving a unique name to each subclass instead of
relying only on namespaces

 #endif
 }
 
 NativeNotificationDisplayService::~NativeNotificationDisplayService() = default;
 
 void NativeNotificationDisplayService::OnNotificationPlatformBridgeReady(
     bool success) {
   UMA_HISTOGRAM_BOOLEAN("Notifications.UsingNativeNotificationCenter", success);
   if (success) {
     notification_bridge_ready_ = true;
@@ skipping 100 matching lines @@
   notification_handlers_.erase(notification_type);
 }
 
 NotificationHandler* NativeNotificationDisplayService::GetNotificationHandler(
     NotificationCommon::Type notification_type) {
   DCHECK(notification_handlers_.find(notification_type) !=
          notification_handlers_.end())
       << notification_type << " is not registered.";
   return notification_handlers_[notification_type].get();
 }