Implement ImageBitmapFactories as a supplementary module.

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': [],
 
@@ skipping 32 matching lines @@
       'filesystem/FileEntrySync.idl',
       'filesystem/FileWriter.idl',
       'filesystem/FileWriterSync.idl',
       'filesystem/Metadata.idl',
       'gamepad/Gamepad.idl',
       'gamepad/GamepadList.idl',
       'geolocation/Coordinates.idl',
       'geolocation/Geolocation.idl',
       'geolocation/Geoposition.idl',
       'geolocation/PositionError.idl',
+      'imagebitmap/ImageBitmapFactories.idl',
       'indexeddb/IDBAny.idl',
       'indexeddb/IDBCursor.idl',
       'indexeddb/IDBCursorWithValue.idl',
       'indexeddb/IDBDatabase.idl',
       'indexeddb/IDBFactory.idl',
       'indexeddb/IDBIndex.idl',
       'indexeddb/IDBKeyRange.idl',
       'indexeddb/IDBObjectStore.idl',
       'indexeddb/IDBOpenDBRequest.idl',
       'indexeddb/IDBRequest.idl',
@@ skipping 275 matching lines @@
       'gamepad/Gamepad.h',
       'gamepad/GamepadList.cpp',
       'gamepad/GamepadList.h',
       'gamepad/NavigatorGamepad.cpp',
       'gamepad/NavigatorGamepad.h',
       'geolocation/Coordinates.cpp',
       'geolocation/Geolocation.cpp',
       'geolocation/GeolocationController.cpp',
       'geolocation/NavigatorGeolocation.cpp',
       'geolocation/NavigatorGeolocation.h',
+      'imagebitmap/ImageBitmapFactories.cpp',
+      'imagebitmap/ImageBitmapFactories.h',
       'indexeddb/DOMWindowIndexedDatabase.cpp',
       'indexeddb/DOMWindowIndexedDatabase.h',
       'indexeddb/IDBAny.cpp',
       'indexeddb/IDBAny.h',
       'indexeddb/IDBCallbacks.h',
       'indexeddb/IDBCursor.cpp',
       'indexeddb/IDBCursor.h',
       'indexeddb/IDBCursorBackendInterface.h',
       'indexeddb/IDBCursorWithValue.cpp',
       'indexeddb/IDBCursorWithValue.h',
@@ skipping 395 matching lines @@
       'indexeddb/IDBKeyPathTest.cpp',
       'indexeddb/IDBRequestTest.cpp',
       'indexeddb/IDBTransactionTest.cpp',
       'websockets/WebSocketDeflaterTest.cpp',
       'websockets/WebSocketExtensionDispatcherTest.cpp',
       'websockets/WebSocketExtensionParserTest.cpp',
       'websockets/WebSocketPerMessageDeflateTest.cpp',
     ],
   },
 }