Implement native web notifications for mac

chrome/chrome_browser.gypi

Index: chrome/chrome_browser.gypi
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 7e012dad347d383d866716a64956b628e44ca6d9..36f2b3fda2c1e82a1238eea765fd408e1d48af3e 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -2053,6 +2053,11 @@
       'browser/push_messaging/push_messaging_notification_manager.cc',
       'browser/push_messaging/push_messaging_notification_manager.h',
     ],
+    # Used on Mac when native notifications are enabled.
+    'chrome_browser_notifications_mac_sources': [
+      'browser/notifications/notification_ui_manager_mac.h',
+      'browser/notifications/notification_ui_manager_mac.mm',
+    ],
     # Used on Android when notifications and java_ui are enabled.
     'chrome_browser_notifications_android_java_ui_sources': [
       'browser/notifications/notification_ui_manager_android.cc',
@@ -3632,6 +3637,11 @@
         ['notifications==1', {
           'sources': [ '<@(chrome_browser_notifications_sources)' ],
           'conditions': [
+            ['OS=="mac"', {
+              'sources': [
+                '<@(chrome_browser_notifications_mac_sources)',
+              ],
+            }],  
             ['android_java_ui==0', {
               'sources': [
                 '<@(chrome_browser_notifications_non_android_sources)',