Rename kAnimatingScrollOnMainThread to kHandlingScrollFromMainThread

ui/events/blink/input_handler_proxy_unittest.cc

Index: ui/events/blink/input_handler_proxy_unittest.cc
diff --git a/ui/events/blink/input_handler_proxy_unittest.cc b/ui/events/blink/input_handler_proxy_unittest.cc
index e8eb2cb28ccf42abfb5604e8318700c4620517b0..695194b860ef25b4198701e1e5dcb87a05280738 100644
--- a/ui/events/blink/input_handler_proxy_unittest.cc
+++ b/ui/events/blink/input_handler_proxy_unittest.cc
@@ -2780,21 +2780,21 @@ TEST_P(InputHandlerProxyTest, MainThreadScrollingMouseWheelHistograms) {
       cc::MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects |
           cc::MainThreadScrollingReason::kThreadedScrollingDisabled |
           cc::MainThreadScrollingReason::kPageOverlay |
-          cc::MainThreadScrollingReason::kAnimatingScrollOnMainThread);
+          cc::MainThreadScrollingReason::kHandlingScrollFromMainThread);
 
   EXPECT_THAT(
       histogram_tester().GetAllSamples("Renderer4.MainThreadWheelScrollReason"),
       testing::ElementsAre(base::Bucket(1, 1), base::Bucket(3, 1),
                            base::Bucket(5, 1)));
 
-  // We only want to record "animating scroll on main thread" reason if it's the
-  // only reason. If it's not the only reason, the "real" reason for scrolling
-  // on main is something else, and we only want to pay attention to that
-  // reason. So we should only include this reason in the histogram when its on
-  // its own.
+  // We only want to record "Handling scroll from main thread" reason if it's
+  // the only reason. If it's not the only reason, the "real" reason for
+  // scrolling on main is something else, and we only want to pay attention to
+  // that reason. So we should only include this reason in the histogram when
+  // its on its own.
   input_handler_->RecordMainThreadScrollingReasonsForTest(
       blink::WebGestureDeviceTouchpad,
-      cc::MainThreadScrollingReason::kAnimatingScrollOnMainThread);
+      cc::MainThreadScrollingReason::kHandlingScrollFromMainThread);
 
   EXPECT_THAT(
       histogram_tester().GetAllSamples("Renderer4.MainThreadWheelScrollReason"),