Start using GrGpuCommandBuffer in GrDrawTarget.

tools/gpu/GrTest.cpp

Index: tools/gpu/GrTest.cpp
diff --git a/tools/gpu/GrTest.cpp b/tools/gpu/GrTest.cpp
index e380b340103193e3ff4765fa592bf0ea5f6b60c4..deb2aa5cfb4ad716fd75cf30d07e0c33a8ebd97e 100644
--- a/tools/gpu/GrTest.cpp
+++ b/tools/gpu/GrTest.cpp
@@ -284,8 +284,6 @@ public:
                               GrPixelConfig srcConfig, DrawPreference*,
                               WritePixelTempDrawInfo*) override { return false; }
 
-    void discard(GrRenderTarget*) override {}
-
     bool onCopySurface(GrSurface* dst,
                        GrSurface* src,
                        const SkIRect& srcRect,
@@ -302,7 +300,7 @@ public:
         return false;
     }
 
-    GrGpuCommandBuffer* createCommandBuffer(const GrRenderTarget& target,
+    GrGpuCommandBuffer* createCommandBuffer(GrRenderTarget* target,
                                             GrGpuCommandBuffer::LoadAndStoreOp colorOp,
                                             GrColor colorClear,
                                             GrGpuCommandBuffer::LoadAndStoreOp stencilOp,
@@ -343,15 +341,6 @@ private:
         return nullptr;
     }
 
-    void onClear(GrRenderTarget*, const SkIRect& rect, GrColor color) override {}
-
-    void onClearStencilClip(GrRenderTarget*, const SkIRect& rect, bool insideClip) override {}
-
-    void onDraw(const GrPipeline&,
-                const GrPrimitiveProcessor&,
-                const GrMesh*,
-                int meshCount) override {}
-
     bool onReadPixels(GrSurface* surface,
                       int left, int top, int width, int height,
                       GrPixelConfig,