Only eglTerminate command buffer displays when no displays are in use

This is a workaround for crbug.com/603223

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1878943008

Review URL: https://codereview.chromium.org/1878943008
1 file changed