Adds PassthroughAbstractTextureImpl

Bug: 827648
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: I75f2ebe01cd6a0af212b7d4a2d823d16f2cbba8b
Reviewed-on: https://chromium-review.googlesource.com/1102085
Commit-Queue: Ted Meyer <[email protected]>
Reviewed-by: Antoine Labour <[email protected]>
Reviewed-by: Frank Liberato <[email protected]>
Cr-Commit-Position: refs/heads/master@{#570290}
6 files changed