rebaseline_server: improve pixel diff reporting
- fix differing pixels count (we weren't always doing this right)
- report number of differing pixels, as well as percentage
- report worst difference per RGB channel
- apply alpha mask to difference image (changed pixels = opaque, unchanged = transparent)
- add tooltips with further explanation of pixel diffs
(SkipBuildbotRuns)
R=mtklein@google.com
Review URL: https://codereview.chromium.org/82823005
git-svn-id: http://skia.googlecode.com/svn/trunk@12366 2bbb7eff-a529-9590-31e7-b0007b416f81
5 files changed