Add the first very basic bits of a geofencing API.

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 37 matching lines @@
       'filesystem/FileWriterCallback.idl',
       'filesystem/FileWriterSync.idl',
       'filesystem/Metadata.idl',
       'filesystem/MetadataCallback.idl',
       'gamepad/Gamepad.idl',
       'gamepad/GamepadButton.idl',
       'gamepad/GamepadEvent.idl',
       'gamepad/GamepadList.idl',
       'gamepad/WebKitGamepad.idl',
       'gamepad/WebKitGamepadList.idl',
+      'geolocation/CircularRegion.idl',
       'geolocation/Coordinates.idl',
+      'geolocation/GeofencingRegion.idl',
       'geolocation/Geolocation.idl',
       'geolocation/Geoposition.idl',
       'geolocation/PositionCallback.idl',
       'geolocation/PositionError.idl',
       'geolocation/PositionErrorCallback.idl',
       'indexeddb/IDBCursor.idl',
       'indexeddb/IDBCursorWithValue.idl',
       'indexeddb/IDBDatabase.idl',
       'indexeddb/IDBFactory.idl',
       'indexeddb/IDBIndex.idl',
@@ skipping 359 matching lines @@
       'gamepad/GamepadEvent.cpp',
       'gamepad/GamepadEvent.h',
       'gamepad/GamepadList.cpp',
       'gamepad/GamepadList.h',
       'gamepad/NavigatorGamepad.cpp',
       'gamepad/NavigatorGamepad.h',
       'gamepad/WebKitGamepad.cpp',
       'gamepad/WebKitGamepad.h',
       'gamepad/WebKitGamepadList.cpp',
       'gamepad/WebKitGamepadList.h',
+      'geolocation/CircularRegion.cpp',
       'geolocation/Coordinates.cpp',
       'geolocation/Geolocation.cpp',
       'geolocation/GeolocationController.cpp',
       'geolocation/GeolocationInspectorAgent.cpp',
       'geolocation/NavigatorGeolocation.cpp',
       'geolocation/NavigatorGeolocation.h',
       'geolocation/PositionOptions.cpp',
       'geolocation/PositionOptions.h',
       'imagebitmap/ImageBitmapFactories.cpp',
       'imagebitmap/ImageBitmapFactories.h',
@@ skipping 521 matching lines @@
       'indexeddb/IDBRequestTest.cpp',
       'indexeddb/IDBTransactionTest.cpp',
       'websockets/WebSocketDeflaterTest.cpp',
       'websockets/WebSocketExtensionDispatcherTest.cpp',
       'websockets/WebSocketExtensionParserTest.cpp',
       'websockets/WebSocketPerMessageDeflateTest.cpp',
       'websockets/WebSocketTest.cpp',
     ],
   },
 }