Fix null dereference in CopyOutputResult's struct traits

The CopyOutputResult's struct traits does not properly handle empty
CopyOutputResults when the format is RGBA_TEXTURE.

Bug: 921358
Change-Id: I103fbcf06682a5eda421ab90e9e9e4b756ab2407
Reviewed-on: https://chromium-review.googlesource.com/c/1409962
Reviewed-by: kylechar <kylechar@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Saman Sami <samans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622676}
1 file changed