Disable ES2 on Linux SDL

TBR=borenet@google.com
BUG=skia:4737
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1550123002

Review URL: https://codereview.chromium.org/1550123002
1 file changed