Remove antialiasing control from GrPaint.

This adds an additional param (of new enum type GrAA) to draws that can antialias and a new enum GrAAType to indicate the AA technique (none, fragment shader computed coverage, msaa).

Some GMs change due to this:
1) In some places we weren't disabling MSAA when the draw was supposed to be unantialiased.
2) Some bounding rect draws that use GrFragmentProcessors were unnecessarily turning on antialiasing, by disabling it a very small number of pixel LSBs change.

Change-Id: I7d8d8793dda70bcd373d09055beb9949c1a8a4d0
Reviewed-on: https://skia-review.googlesource.com/5608
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/GrFixedClip.cpp b/src/gpu/GrFixedClip.cpp
index 9e87588..f664a54 100644
--- a/src/gpu/GrFixedClip.cpp
+++ b/src/gpu/GrFixedClip.cpp
@@ -29,7 +29,7 @@
     }
 }
 
-bool GrFixedClip::isRRect(const SkRect& rtBounds, SkRRect* rr, bool* aa) const {
+bool GrFixedClip::isRRect(const SkRect& rtBounds, SkRRect* rr, GrAA* aa) const {
     if (fWindowRectsState.enabled()) {
         return false;
     }
@@ -39,7 +39,7 @@
             return false;
         }
         rr->setRect(rect);
-        *aa = false;
+        *aa = GrAA::kNo;
         return true;
     }
     return false;