Removed mustSubmitCommandsBeforeCopyOp

The NVidia bug which prompted this appears to have been fixed.

Bug: skia:
Change-Id: If6934bee97ae56ed11d9794b2a5351d004023276
Reviewed-on: https://skia-review.googlesource.com/c/175257
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
3 files changed