Test HTMLImageElement::decode() does not leak the pending promises after resolving or rejecting them.

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".


Decoding a bitmap image - promises will be resolved:
PASS internals.imagePendingDecodePromisesCountForTesting(image) is 0
Decoding a SVG image - promises will be resolved:
PASS internals.imagePendingDecodePromisesCountForTesting(image) is 0
Decoding a broken image - promises will be rejected:
PASS internals.imagePendingDecodePromisesCountForTesting(image) is 0
PASS successfullyParsed is true

TEST COMPLETE