Iterate over instanced draws in GrGpu rather than above GrBatchTarget

src/gpu/GrBatch.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 "GrBatch.h"
 #include "GrBatchTarget.h"
 #include "GrResourceProvider.h"
@@ skipping 32 matching lines @@
 }
 
 void GrBatch::operator delete(void* target) {
     return MemoryPoolAccessor().pool()->release(target);
 }
 
 void* GrBatch::InstancedHelper::init(GrBatchTarget* batchTarget, GrPrimitiveType primType,
                                      size_t vertexStride, const GrIndexBuffer* indexBuffer,
                                      int verticesPerInstance, int indicesPerInstance,
                                      int instancesToDraw) {
-    SkASSERT(!fInstancesRemaining);
     SkASSERT(batchTarget);
     if (!indexBuffer) {
         return NULL;
     }
     const GrVertexBuffer* vertexBuffer;
     int firstVertex;
     int vertexCount = verticesPerInstance * instancesToDraw;
     void* vertices = batchTarget->makeVertSpace(vertexStride, vertexCount,
                                                 &vertexBuffer, &firstVertex);
     if (!vertices) {
         SkDebugf("Vertices could not be allocated for instanced rendering.");
         return NULL;
     }
     SkASSERT(vertexBuffer);
-    fInstancesRemaining = instancesToDraw;
     size_t ibSize = indexBuffer->gpuMemorySize();
-    fMaxInstancesPerDraw = static_cast<int>(ibSize / (sizeof(uint16_t) * indicesPerInstance));
+    int maxInstancesPerDraw = static_cast<int>(ibSize / (sizeof(uint16_t) * indicesPerInstance));
 
     fVertices.initInstanced(primType, vertexBuffer, indexBuffer,
-        firstVertex, verticesPerInstance, indicesPerInstance, &fInstancesRemaining,
-        fMaxInstancesPerDraw);
-    SkASSERT(fMaxInstancesPerDraw > 0);
+        firstVertex, verticesPerInstance, indicesPerInstance, instancesToDraw,
+        maxInstancesPerDraw);
     return vertices;
 }
 
 void* GrBatch::QuadHelper::init(GrBatchTarget* batchTarget, size_t vertexStride, int quadsToDraw) {
     SkAutoTUnref<const GrIndexBuffer> quadIndexBuffer(
         batchTarget->resourceProvider()->refQuadIndexBuffer());
     if (!quadIndexBuffer) {
         SkDebugf("Could not get quad index buffer.");
         return NULL;
     }
     return this->INHERITED::init(batchTarget, kTriangles_GrPrimitiveType, vertexStride,
                                  quadIndexBuffer, kVerticesPerQuad, kIndicesPerQuad, quadsToDraw);
 }