When creating a directly allocated resource in D3D12, also create a
dawn_native::d3d12::Heap to represent that allocation alongside the
ResourceHeapAllocation. This matches D3D12's allocation model when using
CreateCommittedResource and makes residency management much easier.
Bug: dawn:193
Change-Id: I2280863dcfca57bad72962a2b097f8f2d4cc7dad
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/16381
Commit-Queue: Brandon Jones <brandon1.jones@intel.com>
Reviewed-by: Austin Eng <enga@chromium.org>