Prevent masked solid-color draws from being turned into clears

GrRenderTargetContext::drawRect was eliding a BlurMask filtered circle.

Bug: skia:7765
Change-Id: Id98c059f7d786ee5c9bca839c8e099997ff2aedb
Reviewed-on: https://skia-review.googlesource.com/122793
Reviewed-by: Brian Salomon <bsalomon@google.com>
2 files changed