[Compositor event queue] Coalesce gesture scroll&pinch of the same sequence

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 8a0f7e1c902b6cd7be803ed3ac26761ffb1038e8..2fb0050c28ef7bf3d8140db192657702181b6e47 100644
--- a/ui/events/blink/input_handler_proxy_unittest.cc
+++ b/ui/events/blink/input_handler_proxy_unittest.cc
@@ -3087,6 +3087,55 @@ TEST_F(InputHandlerProxyEventQueueTest, VSyncAlignedQueueingTime) {
                                      1);
 }
 
+TEST_F(InputHandlerProxyEventQueueTest, VSyncAlignedCoalesceScrollAndPinch) {
+  // Start scroll in the first frame.
+  EXPECT_CALL(mock_input_handler_, ScrollBegin(testing::_, testing::_))
+      .WillOnce(testing::Return(kImplThreadScrollState));
+  EXPECT_CALL(mock_input_handler_, SetNeedsAnimateInput()).Times(1);
+
+  // GSUs and GPUs in one sequence should be coalesced into 1 GSU and 1 GPU.
+  HandleGestureEvent(WebInputEvent::GestureScrollBegin);
+  HandleGestureEvent(WebInputEvent::GestureScrollUpdate, -20);
+  HandleGestureEvent(WebInputEvent::GestureScrollUpdate, -7);
+  HandleGestureEvent(WebInputEvent::GesturePinchUpdate, 2.0f, 13, 10);
+  HandleGestureEvent(WebInputEvent::GestureScrollUpdate, -10);
+  HandleGestureEvent(WebInputEvent::GestureScrollUpdate, -6);
+  HandleGestureEvent(WebInputEvent::GestureScrollEnd);
+  HandleGestureEvent(WebInputEvent::GesturePinchBegin);
+  HandleGestureEvent(WebInputEvent::GesturePinchUpdate, 0.2f, 2, 20);
+  HandleGestureEvent(WebInputEvent::GesturePinchUpdate, 10.0f, 1, 10);
+  HandleGestureEvent(WebInputEvent::GestureScrollUpdate, -30);
+  HandleGestureEvent(WebInputEvent::GesturePinchUpdate, 0.25f, 3, 30);
+  HandleGestureEvent(WebInputEvent::GestureScrollUpdate, -10);
+  HandleGestureEvent(WebInputEvent::GesturePinchEnd);
+
+  // Only the first GSB was dispatched.
+  EXPECT_EQ(7ul, event_queue().size());
+  EXPECT_EQ(1ul, event_disposition_recorder_.size());
+
+  EXPECT_EQ(WebInputEvent::GestureScrollUpdate,
+            event_queue()[0]->ToWebGestureEvent().type);
+  EXPECT_EQ(-35,
+            event_queue()[0]->ToWebGestureEvent().data.scrollUpdate.deltaY);
+  EXPECT_EQ(WebInputEvent::GesturePinchUpdate,
+            event_queue()[1]->ToWebGestureEvent().type);
+  EXPECT_EQ(2.0f, event_queue()[1]->ToWebGestureEvent().data.pinchUpdate.scale);
+  EXPECT_EQ(WebInputEvent::GestureScrollEnd,
+            event_queue()[2]->ToWebGestureEvent().type);
+  EXPECT_EQ(WebInputEvent::GesturePinchBegin,
+            event_queue()[3]->ToWebGestureEvent().type);
+  EXPECT_EQ(WebInputEvent::GestureScrollUpdate,
+            event_queue()[4]->ToWebGestureEvent().type);
+  EXPECT_EQ(-85,
+            event_queue()[4]->ToWebGestureEvent().data.scrollUpdate.deltaY);
+  EXPECT_EQ(WebInputEvent::GesturePinchUpdate,
+            event_queue()[5]->ToWebGestureEvent().type);
+  EXPECT_EQ(0.5f, event_queue()[5]->ToWebGestureEvent().data.pinchUpdate.scale);
+  EXPECT_EQ(WebInputEvent::GesturePinchEnd,
+            event_queue()[6]->ToWebGestureEvent().type);
+  testing::Mock::VerifyAndClearExpectations(&mock_input_handler_);
+}
+
 INSTANTIATE_TEST_CASE_P(AnimateInput,
                         InputHandlerProxyTest,
                         testing::ValuesIn(test_types));