Add MultiPictureDraw to nanobench

bench/SKPBench.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SKPBench_DEFINED
 #define SKPBench_DEFINED
 
 #include "Benchmark.h"
 #include "SkCanvas.h"
 #include "SkPicture.h"
 
 /**
  * Runs an SkPicture as a benchmark by repeatedly drawing it scaled inside a device clip.
  */
 class SKPBench : public Benchmark {
 public:
-    SKPBench(const char* name, const SkPicture*, const SkIRect& devClip, SkScalar scale);
+    SKPBench(const char* name, const SkPicture*, const SkIRect& devClip, SkScalar scale,
+             bool useMultiPictureDraw);
+    ~SKPBench() SK_OVERRIDE;
 
 protected:
-    virtual const char* onGetName() SK_OVERRIDE;
-    virtual const char* onGetUniqueName() SK_OVERRIDE;
-    virtual bool isSuitableFor(Backend backend) SK_OVERRIDE;
-    virtual void onDraw(const int loops, SkCanvas* canvas) SK_OVERRIDE;
-    virtual SkIPoint onGetSize() SK_OVERRIDE;
+    const char* onGetName() SK_OVERRIDE;
+    const char* onGetUniqueName() SK_OVERRIDE;
+    void onPerCanvasPreDraw(SkCanvas*) SK_OVERRIDE;
+    void onPerCanvasPostDraw(SkCanvas*) SK_OVERRIDE;
+    bool isSuitableFor(Backend backend) SK_OVERRIDE;
+    void onDraw(const int loops, SkCanvas* canvas) SK_OVERRIDE;
+    SkIPoint onGetSize() SK_OVERRIDE;
 
 private:
     SkAutoTUnref<const SkPicture> fPic;
     const SkIRect fClip;
     const SkScalar fScale;
     SkString fName;
     SkString fUniqueName;
 
+    const bool fUseMultiPictureDraw;
+    SkTDArray<SkSurface*> fSurfaces;   // for MultiPictureDraw
+    SkTDArray<SkIRect> fTileRects;     // for MultiPictureDraw
+
     typedef Benchmark INHERITED;
 };
 
 #endif