Workaround Adreno driver issue with stencil clears.

This also removes the "debug wire rect" which was not used and not implemented for Vulkan.

Also some declared but not implemented methods are removed from GrGLGpu.

Bug: skia:5587

Change-Id: I750051e90e6cfbfad6a6fe20792226182f698bcf
Reviewed-on: https://skia-review.googlesource.com/18639
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
9 files changed