Enable coverage when drawing to the stencil buffer.

Currently, we set kEmitTransBlack_BlendOptFlag when drawing to the stencil buffer - but that
prevents masks from being drawn correctly as they receive full coverage and no fragments get
discarded.

R=bsalomon@google.com, robertphillips@google.com

Author: fmalita@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23197003

git-svn-id: http://skia.googlecode.com/svn/trunk@10745 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed