tree ead2fc5ffd45a2d51adff8c8ca02c0c7928f8370
parent 0c685ee188a5e500df25a34fa6edfceb4cbb795c
author msarett <msarett@google.com> 1471213888 -0700
committer Commit bot <commit-bot@chromium.org> 1471213888 -0700

Webp has_alpha is a hint only

The has_alpha bit on webps is a hint only.  We are correct to always
assume that the image may have alpha.
https://groups.google.com/a/webmproject.org/forum/#!msg/webp-discuss/2rFPKOzxuSM/uabYhmSNJAAJ

TBR=scroggo@google.com
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2243153002

Review-Url: https://codereview.chromium.org/2243153002