If the format of the image and the PBO match,
use a vkCmdCopyBufferToImage transfer operation.
Test: angle_end2end_tests --gtest_filter=*PBOCompressedSubImage*
angle_end2end_tests --gtest_filter=*PBOWithMultipleDraws*
dEQP-GLES3.functional.texture.specification.tex*image*d_pbo*
Bug: angleproject:3777
Change-Id: I3f271024a635be113202a16f8893a199c194172d
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1906203Reviewed-by: Cody Northrop <cnorthrop@google.com>
Commit-Queue: Mohan Maiya <m.maiya@samsung.com>
