This cl moves color and coverage off of drawstate.  In an effort to keep this CL manageable, I have left the compute invariant input / output in a bit of a strange state(fixing this will be complicated).

In addition, NVPR makes this very complicated, and I haven't quite figured out a good way to handle it, so for now color and coverage DO live on optstate, but I will figure out some way to refactor that in future CLs.

BUG=skia:

Review URL: https://codereview.chromium.org/783763002
diff --git a/src/gpu/GrSWMaskHelper.h b/src/gpu/GrSWMaskHelper.h
index 54a3897..1eef46e 100644
--- a/src/gpu/GrSWMaskHelper.h
+++ b/src/gpu/GrSWMaskHelper.h
@@ -93,6 +93,7 @@
     static void DrawToTargetWithPathMask(GrTexture* texture,
                                          GrDrawTarget* target,
                                          GrDrawState* drawState,
+                                         GrColor,
                                          const SkIRect& rect);
 
 private: