Rework StyleImage equality determination

StyleFetchedImage and StyleFetchedImageSet needs to take the URL into
consideration because it can contain a fragment that will require the
image to change.

Bug: 643716
Change-Id: If87d3583df0fcb37f872c1423a88f4bd33e8c38f
Reviewed-on: https://chromium-review.googlesource.com/1207390
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#589128}
11 files changed