Update from https://crrev.com/320343

skia/ext/benchmarking_canvas.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SKIA_EXT_BENCHMARKING_CANVAS_H_
 #define SKIA_EXT_BENCHMARKING_CANVAS_H_
 
 #include "base/values.h"
+#include "skia/ext/refptr.h"
 #include "third_party/skia/include/utils/SkNWayCanvas.h"
 
+class SkXfermode;
+
 namespace skia {
 
 class SK_API BenchmarkingCanvas : public SkNWayCanvas {
 public:
   BenchmarkingCanvas(SkCanvas* canvas, unsigned flags = 0);
   ~BenchmarkingCanvas() override;
 
   enum Flags {
-      // TODO(fmalita): add overdraw visualization support
-      // (http://crbug.com/461534)
       kOverdrawVisualization_Flag = 0x01,
   };
 
   // Returns the number of draw commands executed on this canvas.
   size_t CommandCount() const;
 
   // Returns the list of executed draw commands.
   const base::ListValue& Commands() const;
 
   // Return the recorded render time (milliseconds) for a draw command index.
@@ skipping 47 matching lines @@
   void onDrawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y,
                       const SkPaint& paint) override;
 
 private:
   typedef SkNWayCanvas INHERITED;
 
   class AutoOp;
 
   base::ListValue op_records_;
   unsigned flags_;
+  RefPtr<SkXfermode> overdraw_xfermode_;
 };
 
 }
 #endif // SKIA_EXT_BENCHMARKING_CANVAS_H