Improve the curve tessellation subdivision of the path renderers.

src/gpu/GrTessellatingPathRenderer.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrTessellatingPathRenderer.h"
 
 #include "GrBatch.h"
@@ skipping 1374 matching lines @@
     void generateGeometry(GrBatchTarget* batchTarget, const GrPipeline* pipeline) override {
         SkRect pathBounds = fPath.getBounds();
         Comparator c;
         if (pathBounds.width() > pathBounds.height()) {
             c.sweep_lt = sweep_lt_horiz;
             c.sweep_gt = sweep_gt_horiz;
         } else {
             c.sweep_lt = sweep_lt_vert;
             c.sweep_gt = sweep_gt_vert;
         }
-        SkScalar tol = GrPathUtils::scaleToleranceToSrc(SK_Scalar1, fViewMatrix, pathBounds);
+        SkScalar screenSpaceTol = GrPathUtils::kDefaultTolerance;
+        SkScalar tol = GrPathUtils::scaleToleranceToSrc(screenSpaceTol, fViewMatrix, pathBounds);
         int contourCnt;
         int maxPts = GrPathUtils::worstCasePointCount(fPath, &contourCnt, tol);
         if (maxPts <= 0) {
             return;
         }
         if (maxPts > ((int)SK_MaxU16 + 1)) {
             SkDebugf("Path not rendered, too many verts (%d)\n", maxPts);
             return;
         }
         SkPath::FillType fillType = fPath.getFillType();
@@ skipping 105 matching lines @@
     SkMatrix vmi;
     if (!viewM.invert(&vmi)) {
         return false;
     }
     vmi.mapRect(&clipBounds);
     SkAutoTUnref<GrBatch> batch(TessellatingPathBatch::Create(color, path, viewM, clipBounds));
     target->drawBatch(pipelineBuilder, batch);
 
     return true;
 }