Make onPrepareDraws const

src/gpu/batches/GrNinePatch.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 "GrNinePatch.h"
 
 #include "GrBatchFlushState.h"
@@ skipping 67 matching lines @@
                                       GrInitInvariantOutput* coverage,
                                       GrBatchToXPOverrides* overrides) const override {
         color->setUnknownFourComponents();
         coverage->setKnownSingleComponent(0xff);
         overrides->fUsePLSDstRead = false;
     }
 
     SkSTArray<1, Geometry, true>* geoData() { return &fGeoData; }
 
 private:
-    void onPrepareDraws(Target* target) override {
+    void onPrepareDraws(Target* target) const override {
         SkAutoTUnref<const GrGeometryProcessor> gp(create_gp(fOverrides.readsCoverage()));
         if (!gp) {
             SkDebugf("Couldn't create GrGeometryProcessor\n");
             return;
         }
 
         target->initDraw(gp, this->pipeline());
 
         size_t vertexStride = gp->getVertexStride();
         int instanceCount = fGeoData.count();
 
         SkAutoTUnref<const GrIndexBuffer> indexBuffer(
                 target->resourceProvider()->refQuadIndexBuffer());
         InstancedHelper helper;
         void* vertices = helper.init(target, kTriangles_GrPrimitiveType, vertexStride,
                                      indexBuffer, kVertsPerRect,
                                      kIndicesPerRect, instanceCount * kRectsPerInstance);
         if (!vertices || !indexBuffer) {
             SkDebugf("Could not allocate vertices\n");
             return;
         }
 
         for (int i = 0; i < instanceCount; i++) {
             intptr_t verts = reinterpret_cast<intptr_t>(vertices) +
                              i * kRectsPerInstance * kVertsPerRect * vertexStride;
 
-            Geometry& geo = fGeoData[i];
+            const Geometry& geo = fGeoData[i];
             SkNinePatchIter iter(fImageWidth, fImageHeight, geo.fCenter, geo.fDst);
 
             SkRect srcR, dstR;
             while (iter.next(&srcR, &dstR)) {
                 SkPoint* positions = reinterpret_cast<SkPoint*>(verts);
 
                 positions->setRectFan(dstR.fLeft, dstR.fTop,
                                       dstR.fRight, dstR.fBottom, vertexStride);
 
                 SkASSERT(!geo.fViewMatrix.hasPerspective());
@@ skipping 49 matching lines @@
 
     typedef GrVertexBatch INHERITED;
 };
 
 namespace GrNinePatch {
 GrDrawBatch* CreateNonAA(GrColor color, const SkMatrix& viewMatrix, int imageWidth, int imageHeight,
                          const SkIRect& center, const SkRect& dst) {
     return new GrNonAANinePatchBatch(color, viewMatrix, imageWidth, imageHeight, center, dst);
 }
 };