Use Promises for screen.lockOrientation().

Source/modules/modules.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
     # ways.
     'extra_blink_module_idl_files': [],
     'extra_blink_module_files': [],
     # Files for which bindings (.cpp and .h files) will be generated
@@ skipping 599 matching lines @@
       'quota/StorageQuota.cpp',
       'quota/StorageQuota.h',
       'quota/StorageQuotaCallback.h',
       'quota/StorageQuotaCallbacksImpl.cpp',
       'quota/StorageQuotaCallbacksImpl.h',
       'quota/StorageQuotaClient.cpp',
       'quota/StorageQuotaClient.h',
       'quota/StorageUsageCallback.h',
       'quota/WorkerNavigatorStorageQuota.cpp',
       'quota/WorkerNavigatorStorageQuota.h',
+      'screen_orientation/LockOrientationCallback.cpp',
+      'screen_orientation/LockOrientationCallback.h',
       'screen_orientation/ScreenOrientation.cpp',
       'screen_orientation/ScreenOrientation.h',
       'screen_orientation/ScreenOrientationController.cpp',
       'screen_orientation/ScreenOrientationController.h',
       'screen_orientation/ScreenOrientationDispatcher.cpp',
       'screen_orientation/ScreenOrientationDispatcher.h',
       'serviceworkers/Cache.cpp',
       'serviceworkers/Cache.h',
       'serviceworkers/Client.cpp',
       'serviceworkers/Client.h',
@@ skipping 307 matching lines @@
       'indexeddb/IDBKeyPathTest.cpp',
       'indexeddb/IDBRequestTest.cpp',
       'indexeddb/IDBTransactionTest.cpp',
       'websockets/WebSocketDeflaterTest.cpp',
       'websockets/WebSocketExtensionDispatcherTest.cpp',
       'websockets/WebSocketExtensionParserTest.cpp',
       'websockets/WebSocketPerMessageDeflateTest.cpp',
     ],
   },
 }