We could consider having the clear color to be a part of the TextureDescriptor. Justification:

1. D3D12 specifically has this specified at resource creation and I vaguely recall this matching some of the specifics of AMD hardware (but need to investigate more to confirm this).
2. it's not a common thing to vary the clear color for a particular texture.
3. straightforward clear operation (in RenderPassDescriptor) just being an enum of "clear"/"load" (related to Consolidate *loadOp and clear* into a unioned field #283 and Optional clear values #276).
4. we could still provide an API for clearing with custom values, perhaps as a simple clearImage that is performed out of the pass, or clearAttachment within a pass.