Start using GrGpuCommandBuffer in GrDrawTarget.

src/gpu/GrBatchFlushState.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 "GrBatchFlushState.h"
 
 #include "GrBatchAtlas.h"
 #include "GrPipeline.h"
 
 GrBatchFlushState::GrBatchFlushState(GrGpu* gpu, GrResourceProvider* resourceProvider)
     : fGpu(gpu)
     , fResourceProvider(resourceProvider)
+    , fCommandBuffer(nullptr)
     , fVertexPool(gpu)
     , fIndexPool(gpu)
     , fLastIssuedToken(GrBatchDrawToken::AlreadyFlushedToken())
     , fLastFlushedToken(0) {}
 
 void* GrBatchFlushState::makeVertexSpace(size_t vertexSize, int vertexCount,
                                          const GrBuffer** buffer, int* startVertex) {
     return fVertexPool.makeSpace(vertexSize, vertexCount, buffer, startVertex);
 }
 
 uint16_t* GrBatchFlushState::makeIndexSpace(int indexCount,
                                             const GrBuffer** buffer, int* startIndex) {
     return reinterpret_cast<uint16_t*>(fIndexPool.makeSpace(indexCount, buffer, startIndex));
 }