Jiawei Shao f4df7916ca Add validation on the buffer-to-buffer copies within same buffer
This patch adds the validation on the buffer-to-buffer copies within the
same buffer. When the source and destination buffer are the same one in
CopyBufferToBuffer(), the copy region cannot overlap or it will cause
undefined behaviors on Metal and Vulkan.

BUG=dawn:17
TEST=dawn_unittests, dawn_end2end_tests

Change-Id: I63ab790787ec0a973ae22787a9348bddfb6a5373
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/21602
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Jiawei Shao <jiawei.shao@intel.com>
2020-05-13 00:17:15 +00:00
..