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

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 51660ff0f4b30780c6efcfccc817f6078363aaf5..1c0e8bb94ae19be9064a0435bf266664c22f85e7 100644
--- a/ui/events/blink/input_handler_proxy_unittest.cc
+++ b/ui/events/blink/input_handler_proxy_unittest.cc
@@ -3025,32 +3025,26 @@ TEST(SynchronousInputHandlerProxyTest, SetOffset) {
   testing::Mock::VerifyAndClearExpectations(&mock_synchronous_input_handler);
 }
 
-TEST_P(InputHandlerProxyTest, MainThreadScrollingMouseWheelHistograms) {
+// Only test NotScrollingOnMain, the actual main thread scrolling reasons
+// are tested in EventHandlerTest.MainThreadScrollingReasonRecordTest
+TEST_P(InputHandlerProxyTest, MainThreadScrollingReasonHistograms) {
+  // Test wheel scroll
   input_handler_->RecordMainThreadScrollingReasonsForTest(
       blink::WebGestureDeviceTouchpad,
-      cc::MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects |
-          cc::MainThreadScrollingReason::kThreadedScrollingDisabled |
-          cc::MainThreadScrollingReason::kPageOverlay |
-          cc::MainThreadScrollingReason::kHandlingScrollFromMainThread);
+      cc::MainThreadScrollingReason::kNotScrollingOnMain);
 
   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 "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.
+      testing::ElementsAre(base::Bucket(0, 1)));
+
+  // Test touch scroll
   input_handler_->RecordMainThreadScrollingReasonsForTest(
-      blink::WebGestureDeviceTouchpad,
-      cc::MainThreadScrollingReason::kHandlingScrollFromMainThread);
+      blink::WebGestureDeviceTouchscreen,
+      cc::MainThreadScrollingReason::kNotScrollingOnMain);
 
-  EXPECT_THAT(
-      histogram_tester().GetAllSamples("Renderer4.MainThreadWheelScrollReason"),
-      testing::ElementsAre(base::Bucket(1, 1), base::Bucket(3, 1),
-                           base::Bucket(5, 1), base::Bucket(14, 1)));
+  EXPECT_THAT(histogram_tester().GetAllSamples(
+                  "Renderer4.MainThreadGestureScrollReason"),
+              testing::ElementsAre(base::Bucket(0, 1)));
 }
 
 TEST_P(InputHandlerProxyTest, GestureScrollingThreadStatusHistogram) {