Use Fetch load image for Canvas tests

Bug: 1275750
Change-Id: Ibf8cd9828232e737e91a53b3fa811c5b026aa3af
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4334325


Reviewed-by: Justin Novosad <junov@chromium.org>
Commit-Queue: Yi Xu <yiyix@google.com>
Cr-Commit-Position: refs/heads/main@{#1118228}