Revert "allow client to pass null if there are no uniforms"

This reverts commit 0185eb19d417fe2480da345dfcfdc62aad57d468.

Reason for revert: Asserts on ASAN bots

Original change's description:
> allow client to pass null if there are no uniforms
> 
> Change-Id: I788574ccd1f66cfa29556d7d84ae813d108a39c7
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/271318
> Reviewed-by: Mike Reed <reed@google.com>
> Commit-Queue: Mike Reed <reed@google.com>

TBR=brianosman@google.com,reed@google.com

Change-Id: I497b657095570055066c4964150bfb16cd33b027
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/271697
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2 files changed