Update from https://crrev.com/320343

skia/ext/benchmarking_canvas.h

Index: skia/ext/benchmarking_canvas.h
diff --git a/skia/ext/benchmarking_canvas.h b/skia/ext/benchmarking_canvas.h
index 4f2e25718e5060822ed8ea12a8cbf83952f853f5..a33c42d9fd1ac9d274348f57b11f20580b5470ee 100644
--- a/skia/ext/benchmarking_canvas.h
+++ b/skia/ext/benchmarking_canvas.h
@@ -6,8 +6,11 @@
 #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 {
@@ -16,8 +19,6 @@ public:
   ~BenchmarkingCanvas() override;
 
   enum Flags {
-      // TODO(fmalita): add overdraw visualization support
-      // (http://crbug.com/461534)
       kOverdrawVisualization_Flag = 0x01,
   };
 
@@ -85,6 +86,7 @@ private:
 
   base::ListValue op_records_;
   unsigned flags_;
+  RefPtr<SkXfermode> overdraw_xfermode_;
 };
 
 }