Move logic of recording main thread scrolling reasons from cc to blink::ScrollManager

third_party/WebKit/Source/core/input/ScrollManager.h

Index: third_party/WebKit/Source/core/input/ScrollManager.h
diff --git a/third_party/WebKit/Source/core/input/ScrollManager.h b/third_party/WebKit/Source/core/input/ScrollManager.h
index 34cb0a22e7516e5bd13c7d778b2d4c1a0dbd7bbd..01aaf696a4cf525b21f2c34e2b9967dcdf8d478f 100644
--- a/third_party/WebKit/Source/core/input/ScrollManager.h
+++ b/third_party/WebKit/Source/core/input/ScrollManager.h
@@ -91,6 +91,11 @@ class CORE_EXPORT ScrollManager
   void clearResizeScrollableArea(bool shouldNotBeNull);
   void setResizeScrollableArea(PaintLayer*, IntPoint);
 
+  // Record main thread scrolling reasons. This should be no-op;

[bokan, 2017/03/24 17:55:54]

Why does this say it should be a no-op? Recording a histogram is an op :)

[yigu, 2017/03/27 21:02:07]

Done.

+  uint32_t computeMainThreadScrollingReasons(const Node&);
+  void recordMainThreadScrollingReasons(const uint32_t reasons,
+                                        const WebGestureDevice);
+
  private:
   WebInputEventResult handleGestureScrollUpdate(const WebGestureEvent&);
   WebInputEventResult handleGestureScrollBegin(const WebGestureEvent&);