Add NotificationOptions.actions so websites can provide buttons (blink)

Source/modules/modules.gypi

 {
   'includes': [
     '../core/core_generated.gypi',
     'modules_generated.gypi',
   ],
   'variables': {
     # Experimental hooks for embedder to provide extra IDL and source files.
     #
     # Note: this is not a supported API. If you rely on this, you will be broken
     # from time to time as the code generator changes in backward incompatible
@@ skipping 426 matching lines @@
       'indexeddb/IDBVersionChangeEventInit.idl',
       'mediastream/MediaStreamEventInit.idl',
       'mediastream/RTCDTMFToneChangeEventInit.idl',
       'mediastream/RTCIceCandidateInit.idl',
       'mediastream/RTCSessionDescriptionInit.idl',
       'navigatorconnect/ServicePortConnectEventInit.idl',
       'navigatorconnect/ServicePortConnectOptions.idl',
       'navigatorconnect/ServicePortConnectResponse.idl',
       'navigatorconnect/ServicePortMatchOptions.idl',
       'notifications/GetNotificationOptions.idl',
+      'notifications/NotificationAction.idl',
       'notifications/NotificationEventInit.idl',
       'notifications/NotificationOptions.idl',
       'permissions/MidiPermissionDescriptor.idl',
       'permissions/PermissionDescriptor.idl',
       'permissions/PushPermissionDescriptor.idl',
       'presentation/DefaultSessionStartEventInit.idl',
       'push_messaging/PushEventInit.idl',
       'push_messaging/PushSubscriptionOptions.idl',
       'serviceworkers/ClientQueryOptions.idl',
       'serviceworkers/ExtendableEventInit.idl',
@@ skipping 94 matching lines @@
       '<(blink_modules_output_dir)/navigatorconnect/ServicePortConnectEventInit.cpp',
       '<(blink_modules_output_dir)/navigatorconnect/ServicePortConnectEventInit.h',
       '<(blink_modules_output_dir)/navigatorconnect/ServicePortConnectOptions.cpp',
       '<(blink_modules_output_dir)/navigatorconnect/ServicePortConnectOptions.h',
       '<(blink_modules_output_dir)/navigatorconnect/ServicePortConnectResponse.cpp',
       '<(blink_modules_output_dir)/navigatorconnect/ServicePortConnectResponse.h',
       '<(blink_modules_output_dir)/navigatorconnect/ServicePortMatchOptions.cpp',
       '<(blink_modules_output_dir)/navigatorconnect/ServicePortMatchOptions.h',
       '<(blink_modules_output_dir)/notifications/GetNotificationOptions.cpp',
       '<(blink_modules_output_dir)/notifications/GetNotificationOptions.h',
+      '<(blink_modules_output_dir)/notifications/NotificationAction.cpp',
+      '<(blink_modules_output_dir)/notifications/NotificationAction.h',
       '<(blink_modules_output_dir)/notifications/NotificationEventInit.cpp',
       '<(blink_modules_output_dir)/notifications/NotificationEventInit.h',
       '<(blink_modules_output_dir)/notifications/NotificationOptions.cpp',
       '<(blink_modules_output_dir)/notifications/NotificationOptions.h',
       '<(blink_modules_output_dir)/permissions/MidiPermissionDescriptor.cpp',
       '<(blink_modules_output_dir)/permissions/MidiPermissionDescriptor.h',
       '<(blink_modules_output_dir)/permissions/PermissionDescriptor.cpp',
       '<(blink_modules_output_dir)/permissions/PermissionDescriptor.h',
       '<(blink_modules_output_dir)/permissions/PushPermissionDescriptor.cpp',
       '<(blink_modules_output_dir)/permissions/PushPermissionDescriptor.h',
@@ skipping 1173 matching lines @@
       'webaudio/AudioBasicProcessorHandlerTest.cpp',
       'webaudio/ConvolverNodeTest.cpp',
       'webaudio/DynamicsCompressorNodeTest.cpp',
       'webaudio/ScriptProcessorNodeTest.cpp',
       'webaudio/StereoPannerNodeTest.cpp',
       'websockets/DOMWebSocketTest.cpp',
       'websockets/DocumentWebSocketChannelTest.cpp',
     ],
   },
 }