This CL adds support for chunking large commands by first serializing
large commands first into a separate buffer, and then sending the
buffer data chunk by chunk.
This code path is used for large writeBuffer and writeTexture, as well
as the inline memory transfer service for buffer mapping. The transfer
for writeBuffer and writeTexture will be optimized further in Chrome,
and the inline memory transfer service is currently used only in tests.
Bug: chromium:1123861, chromium:951558
Change-Id: I02491a44e653e2383174958d9c3d4a4db6fd7bde
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/28882
Commit-Queue: Austin Eng <enga@chromium.org>
Reviewed-by: Stephen White <senorblanco@chromium.org>