Mark existing Skia suppressions for rebaseline.

BUG=344497,356644,365698
TBR=caryclark@google.com

Review URL: https://codereview.chromium.org/264483005

git-svn-id: svn://svn.chromium.org/blink/trunk@172994 bbb929c8-8fbe-4397-9dbb-9b2b20218538