UMA metrics for use count of wheel and touch scrolls.

third_party/WebKit/Source/web/WebViewImpl.cpp

Index: third_party/WebKit/Source/web/WebViewImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebViewImpl.cpp b/third_party/WebKit/Source/web/WebViewImpl.cpp
index f934dd0b95c4667b4254bb403d27dd5059be6195..dea51afb9aa0c261f5b5df45ba19c03831a271c9 100644
--- a/third_party/WebKit/Source/web/WebViewImpl.cpp
+++ b/third_party/WebKit/Source/web/WebViewImpl.cpp
@@ -4013,6 +4013,17 @@ void WebViewImpl::applyViewportDeltas(
     mainFrameImpl()->frameView()->didUpdateElasticOverscroll();
 }
 
+void WebViewImpl::RecordWheelAndTouchScrollingCount(bool hasScrolledByWheel,
+                                                    bool hasScrolledByTouch) {
+  if (!page() || !page()->mainFrame())
+    return;
+
+  if (hasScrolledByWheel)
+    UseCounter::count(page()->mainFrame(), UseCounter::ScrollByWheel);
+  if (hasScrolledByTouch)
+    UseCounter::count(page()->mainFrame(), UseCounter::ScrollByTouch);
+}
+
 void WebViewImpl::updateLayerTreeViewport() {
   if (!page() || !m_layerTreeView)
     return;