Reimplement ImageElementBase::IsOpaque

Don't use Element::ImageContents(), which is a method primarily meant
for the WebElement interface (and not actually implemented by
SVGImageElement.) Use the local ImageLoader and related helpers instead.

Bug: 773272
Change-Id: Idbbf8a85b6905e072db2bf4ac12e38ff9756025d
Reviewed-on: https://chromium-review.googlesource.com/768872
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#516437}
1 file changed