This driver bug has been fixed in 20.19.15.4539.

BUG=chromium:644610
TEST=dEQP-GLES3.functional.fbo.blit.default_framebuffer.rgb565*

Change-Id: I37556304ed4f70771fb88b792c01b6be5b3aa294
Reviewed-on: https://chromium-review.googlesource.com/424103Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>