Add GpuCommandBuffer support.

src/gpu/GrGpu.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGpu_DEFINED
 #define GrGpu_DEFINED
 
+#include "GrGpuCommandBuffer.h"
 #include "GrPipelineBuilder.h"
 #include "GrProgramDesc.h"
 #include "GrSwizzle.h"
 #include "GrAllocator.h"
 #include "GrTextureParamsAdjuster.h"
 #include "GrTypes.h"
 #include "GrXferProcessor.h"
 #include "SkPath.h"
 #include "SkTArray.h"
 
@@ skipping 332 matching lines @@
         // If sample locations are supported, contains the subpixel locations at which the GPU will
         // sample. Pixel center is at (.5, .5) and (0, 0) indicates the top left corner.
         SkAutoTDeleteArray<const SkPoint>  fSampleLocations;
     };
 
     // Finds a render target's multisample specs. The stencil settings are only needed to flush the
     // draw state prior to querying multisample information; they should not have any effect on the
     // multisample information itself.
     const MultisampleSpecs& getMultisampleSpecs(GrRenderTarget*, const GrStencilSettings&);
 
+    // Creates a GrGpuCommandBuffer in which the GrDrawTarget can send draw commands to instead of
+    // directly to the Gpu object.
+    virtual GrGpuCommandBuffer* createCommandBuffer(const GrRenderTarget& target,
+                                                    GrGpuCommandBuffer::LoadAndStoreOp colorOp,
+                                                    GrColor colorClear,
+                                                    GrGpuCommandBuffer::LoadAndStoreOp stencilOp,
+                                                    GrColor stencilClear) = 0;
+
     // We pass in an array of meshCount GrMesh to the draw. The backend should loop over each
     // GrMesh object and emit a draw for it. Each draw will use the same GrPipeline and
     // GrPrimitiveProcessor. This may fail if the draw would exceed any resource limits (e.g.
     // number of vertex attributes is too large).
     bool draw(const GrPipeline&,
               const GrPrimitiveProcessor&,
               const GrMesh*,
               int meshCount);
 
     // Called by drawtarget when flushing.
@@ skipping 230 matching lines @@
     SkTArray<const MultisampleSpecs*, true>                             fMultisampleSpecsMap;
     GrTAllocator<MultisampleSpecs>                                      fMultisampleSpecsAllocator;
     // The context owns us, not vice-versa, so this ptr is not ref'ed by Gpu.
     GrContext*                                                          fContext;
 
     friend class GrPathRendering;
     typedef SkRefCnt INHERITED;
 };
 
 #endif