Extract NotificationDisplayServiceDelegate into its own file

I anticipate needing it for notifications for lacros. See
go/lacros and go/lacros-notifications.

Also, clean up BUILD.gn slightly -- enable_native_notifications is
always true on Chrome OS.

Bug: 1113889
Change-Id: I6c3bc7f81f81157568f8c1b2969f98a82a037b6d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2339450
Commit-Queue: Jun Mukai <mukai@chromium.org>
Auto-Submit: James Cook <jamescook@chromium.org>
Reviewed-by: Jun Mukai <mukai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#795968}

chrome/browser/BUILD.gn

@@ -3817,6 +3817,7 @@ static_library("browser") {
   }
 
   if (is_chromeos) {
+    assert(enable_native_notifications)
     sources += [
       "apps/app_service/arc_activity_adaptive_icon_impl.cc",
       "apps/app_service/arc_activity_adaptive_icon_impl.h",
@@ -3929,6 +3930,9 @@ static_library("browser") {
       "notifications/chrome_ash_message_center_client.h",
       "notifications/extension_notifier_controller.cc",
       "notifications/extension_notifier_controller.h",
+      "notifications/notification_platform_bridge_chromeos.cc",
+      "notifications/notification_platform_bridge_chromeos.h",
+      "notifications/notification_platform_bridge_delegate.h",
       "notifications/notifier_controller.h",
       "notifications/web_page_notifier_controller.cc",
       "notifications/web_page_notifier_controller.h",
@@ -4005,13 +4009,6 @@ static_library("browser") {
       "//ui/ozone",
     ]
     allow_circular_includes_from += [ "//chrome/browser/chromeos" ]
-
-    if (enable_native_notifications) {
-      sources += [
-        "notifications/notification_platform_bridge_chromeos.cc",
-        "notifications/notification_platform_bridge_chromeos.h",
-      ]
-    }
   } else {  # Non - ChromeOS.
     sources += [
       "fullscreen.h",

chrome/browser/notifications/chrome_ash_message_center_client.h

@@ -9,7 +9,7 @@
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "chrome/browser/notifications/notification_platform_bridge.h"
-#include "chrome/browser/notifications/notification_platform_bridge_chromeos.h"
+#include "chrome/browser/notifications/notification_platform_bridge_delegate.h"
 #include "chrome/browser/notifications/notifier_controller.h"
 
 // This class serves as Chrome's AshMessageCenterClient, as well as the

chrome/browser/notifications/notification_platform_bridge_chromeos.h

@@ -11,39 +11,11 @@
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "chrome/browser/notifications/notification_platform_bridge.h"
+#include "chrome/browser/notifications/notification_platform_bridge_delegate.h"
 #include "chrome/browser/notifications/profile_notification.h"
 
 class ChromeAshMessageCenterClient;
 
-// The interface that a NotificationPlatformBridge uses to pass back information
-// and interactions from the native notification system. TODO(estade): this
-// should be hoisted into its own file, implemented by
-// NativeNotificationDisplayService, and used by other platforms'
-// NotificationPlatformBridge implementations. See http://crbug.com/776443
-class NotificationPlatformBridgeDelegate {
- public:
-  // To be called when a notification is closed. Each notification can be closed
-  // at most once.
-  virtual void HandleNotificationClosed(const std::string& id,
-                                        bool by_user) = 0;
-
-  // To be called when the body of a notification is clicked.
-  virtual void HandleNotificationClicked(const std::string& id) = 0;
-
-  // To be called when a button in a notification is clicked.
-  virtual void HandleNotificationButtonClicked(
-      const std::string& id,
-      int button_index,
-      const base::Optional<base::string16>& reply) = 0;
-
-  // To be called when the settings button in a notification is clicked.
-  virtual void HandleNotificationSettingsButtonClicked(
-      const std::string& id) = 0;
-
-  // To be called when a notification (source) should be disabled.
-  virtual void DisableNotification(const std::string& id) = 0;
-};
-
 // A platform bridge that uses Ash's message center to display notifications.
 class NotificationPlatformBridgeChromeOs
     : public NotificationPlatformBridge,

chrome/browser/notifications/notification_platform_bridge_delegate.h

+// Copyright 2020 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_NOTIFICATIONS_NOTIFICATION_PLATFORM_BRIDGE_DELEGATE_H_
+#define CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_PLATFORM_BRIDGE_DELEGATE_H_
+
+#include <string>
+
+#include "base/optional.h"
+#include "base/strings/string16.h"
+
+// The interface that a NotificationPlatformBridge uses to pass back information
+// and interactions from the native notification system.
+// TODO(estade): This should be implemented by NativeNotificationDisplayService,
+// and used by other platforms' NotificationPlatformBridge implementations. See
+// http://crbug.com/776443
+class NotificationPlatformBridgeDelegate {
+ public:
+  // To be called when a notification is closed. Each notification can be closed
+  // at most once.
+  virtual void HandleNotificationClosed(const std::string& id,
+                                        bool by_user) = 0;
+
+  // To be called when the body of a notification is clicked.
+  virtual void HandleNotificationClicked(const std::string& id) = 0;
+
+  // To be called when a button in a notification is clicked.
+  virtual void HandleNotificationButtonClicked(
+      const std::string& id,
+      int button_index,
+      const base::Optional<base::string16>& reply) = 0;
+
+  // To be called when the settings button in a notification is clicked.
+  virtual void HandleNotificationSettingsButtonClicked(
+      const std::string& id) = 0;
+
+  // To be called when a notification (source) should be disabled.
+  virtual void DisableNotification(const std::string& id) = 0;
+
+ protected:
+  virtual ~NotificationPlatformBridgeDelegate() = default;
+};
+
+#endif  // CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_PLATFORM_BRIDGE_DELEGATE_H_