fix for default path renderer draws harlines without bloating

src/gpu/batches/GrDefaultPathRenderer.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrDefaultPathRenderer.h"
 
 #include "GrBatchFlushState.h"
@@ skipping 368 matching lines @@
 
     DefaultPathBatch(const Geometry& geometry, uint8_t coverage, const SkMatrix& viewMatrix,
                      bool isHairline, const SkRect& devBounds)
         : INHERITED(ClassID()) {
         fBatch.fCoverage = coverage;
         fBatch.fIsHairline = isHairline;
         fBatch.fViewMatrix = viewMatrix;
         fGeoData.push_back(geometry);
 
         this->setBounds(devBounds);
+
+        // This is b.c. hairlines are notionally infinitely thin so without expansion
+        // two overlapping lines could be reordered even though they hit the same pixels.
+        if (isHairline) {
+            fBounds.outset(0.5f, 0.5f);
+        }
     }
 
     bool onCombineIfPossible(GrBatch* t, const GrCaps& caps) override {
         DefaultPathBatch* that = t->cast<DefaultPathBatch>();
         if (!GrPipeline::CanCombine(*this->pipeline(), this->bounds(), *that->pipeline(),
                                      that->bounds(), caps)) {
             return false;
         }
 
         if (this->color() != that->color()) {
@@ skipping 357 matching lines @@
     geometry.fColor = color;
     geometry.fPath = path;
     geometry.fTolerance = srcSpaceTol;
 
     viewMatrix.mapRect(&bounds);
     uint8_t coverage = GrRandomCoverage(random);
     return DefaultPathBatch::Create(geometry, coverage, viewMatrix, true, bounds);
 }
 
 #endif