Mark Skia suppressions for rebasline.

Unreviewed gardening.

BUG=/341448,344497
TBR=robertphillips@google.com

Review URL: https://codereview.chromium.org/183123002

git-svn-id: svn://svn.chromium.org/blink/trunk@168027 bbb929c8-8fbe-4397-9dbb-9b2b20218538