Revert of Make ImageBitmap Transferable

third_party/WebKit/LayoutTests/fast/canvas/resources/canvas-ImageBitmap-transferable.js

-self.onmessage = function(e) {
-  // Worker does two things:
-  // 1. call createImageBitmap() from the ImageBitmap that is transfered
-  // from the main thread, which verifies that createImageBitmap(ImageBitmap)
-  // works on the worker thread.
-  // 2. send the created ImageBitmap back to the main thread, the
-  // main thread exam the property of this ImageBitmap to make sure
-  // the transfer between main and worker thread didn't lose data
-  createImageBitmap(e.data.data).then(imageBitmap => {
-    postMessage({data: imageBitmap}, [imageBitmap]);
-  });
-};