Tested with angle_*_tests and WebGL CTS in Chrome Canary on Windows. Passed with no regressions.

Change-Id: Ied0a32ea75565ef19b8e87bed8bdd555b74edee3
Reviewed-on: https://chromium-review.googlesource.com/234110Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Tested-by: Dongseong Hwang <dongseong.hwang@intel.com>
Reviewed-by: Kenneth Russell <kbr@chromium.org>