WebNN: discard empty writes for DML
Fixes an issue where writeBuffer() with empty data would
cause the DML backend to fail because zero-sized resources
cannot exist. This change aligns DML behavior with the other
backends by simply treating it as a no-op.
Bug: 350878615
Change-Id: I92af7e461cedd3e7828f63dc113dfbe73273f32f
Cq-Include-Trybots: luci.chromium.try:win11-blink-rel
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5766133
Reviewed-by: ningxin hu ningxin.hu@intel.com
Commit-Queue: Bryan Bernhart bryan.bernhart@intel.com
Reviewed-by: Rafael Cintron rafael.cintron@microsoft.com
Cr-Commit-Position: refs/heads/main@{#1340470}