Basic CPU support for VisualBench.

tools/VisualBench/CpuWrappedBenchmark.h

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ */
+
+#ifndef CpuWrappedBenchmark_DEFINED
+#define CpuWrappedBenchmark_DEFINED
+
+#include "Benchmark.h"
+#include "SkSurface.h"
+
+class CpuWrappedBenchmark : public Benchmark {
+public:
+    // Takes ownership of caller's ref on `bench`.
+    explicit CpuWrappedBenchmark(Benchmark* bench) : fBench(bench) {}
+
+    const char* onGetName()       override { return fBench->getName(); }
+    const char* onGetUniqueName() override { return fBench->getUniqueName(); }
+
+    void onDraw(int loops, SkCanvas* canvas) override {
+        // TODO: use onPreDraw() to move offscreen allocation/deallocation out of timing.
+        SkAutoTUnref<SkSurface> offscreen(SkSurface::NewRaster(canvas->imageInfo()));
+
+        fBench->draw(loops, offscreen->getCanvas());
+        SkAutoTUnref<SkImage> image(offscreen->newImageSnapshot());
+        canvas->drawImage(image, 0,0);
+    }
+
+private:
+    SkAutoTUnref<Benchmark> fBench;
+};
+
+#endif//CpuWrappedBenchmark_DEFINED