Do not apply hairline optimization for paths if nv_path_rendering is used

src/gpu/GrDrawTarget.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrDrawTarget_DEFINED
 #define GrDrawTarget_DEFINED
 
@@ skipping 82 matching lines @@
      * following assumptions are made:
      *    1. The caller intends to somehow specify coverage. This can be
      *       specified either by enabling a coverage stage on the GrDrawState or
      *       via the vertex layout.
      *    2. Other than enabling coverage stages or enabling coverage in the
      *       layout, the current configuration of the target's GrDrawState is as
      *       it will be at draw time.
      */
     bool canApplyCoverage() const;
 
+    /** When we're using coverage AA but the blend is incompatible (given gpu
+     * limitations) we should disable AA. */
+    bool shouldDisableCoverageAAForBlend() {
+        // Enable below if we should draw with AA even when it produces
+        // incorrect blending.
+        // return false;
+        return !this->canApplyCoverage();
+    }
+
     /**
      * Given the current draw state and hw support, will HW AA lines be used (if
      * a line primitive type is drawn)?
      */
     bool willUseHWAALines() const;
 
     /**
      * There are three types of "sources" of geometry (vertices and indices) for
      * draw calls made on the target. When performing an indexed draw, the
      * indices and vertices can use different source types. Once a source is
@@ skipping 764 matching lines @@
     const GrClipData*                                               fClip;
     GrDrawState*                                                    fDrawState;
     GrDrawState                                                     fDefaultDrawState;
     // The context owns us, not vice-versa, so this ptr is not ref'ed by DrawTarget.
     GrContext*                                                      fContext;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif