Due to either Adreno bug in glBufferSubData,
or generic Android bug in ANativeWindow_setBuffersGeometry.
BUG=angleproject:1415
TEST=ReadPixelsPBOTest.SubDataOffsetPreservesContents
Change-Id: If55f6ad4eacde98cfdbc46a61cc9fb479b779297
Reviewed-on: https://chromium-review.googlesource.com/353396Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
