Add GpuCommandBuffer support.

tools/gpu/GrTest.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrTest.h"
 
 #include "GrBatchAtlas.h"
@@ skipping 283 matching lines @@
                                const GrStencilSettings&,
                                int* effectiveSampleCnt,
                                SkAutoTDeleteArray<SkPoint>*) override {
         *effectiveSampleCnt = rt->desc().fSampleCnt;
     }
 
     bool initCopySurfaceDstDesc(const GrSurface* src, GrSurfaceDesc* desc) const override {
         return false;
     }
 
+    GrGpuCommandBuffer* createCommandBuffer(const GrRenderTarget& target,
+                                            GrGpuCommandBuffer::LoadAndStoreOp colorOp,
+                                            GrColor colorClear,
+                                            GrGpuCommandBuffer::LoadAndStoreOp stencilOp,
+                                            GrColor stencilClear) override {
+        return nullptr;
+    }
+
     void drawDebugWireRect(GrRenderTarget*, const SkIRect&, GrColor) override {};
 
 private:
     void onResetContext(uint32_t resetBits) override {}
 
     void xferBarrier(GrRenderTarget*, GrXferBarrierType) override {}
 
     GrTexture* onCreateTexture(const GrSurfaceDesc& desc, SkBudgeted budgeted,
                                const SkTArray<GrMipLevel>& texels) override {
         return nullptr;
@@ skipping 83 matching lines @@
     SkASSERT(nullptr == fGpu);
     fGpu = new MockGpu(this, options);
     SkASSERT(fGpu);
     this->initCommon(options);
 
     // We delete these because we want to test the cache starting with zero resources. Also, none of
     // these objects are required for any of tests that use this context. TODO: make stop allocating
     // resources in the buffer pools.
     fDrawingManager->abandon();
 }