Notify Blink about start of gesture scroll through a queued event.

content/browser/renderer_host/input/input_router_impl_unittest.cc

Index: content/browser/renderer_host/input/input_router_impl_unittest.cc
diff --git a/content/browser/renderer_host/input/input_router_impl_unittest.cc b/content/browser/renderer_host/input/input_router_impl_unittest.cc
index e5d16cba8a259c40ff3f0788e5459dbb2e49b3e2..d33bb8ecf289bd0d6ff652a784f81998bb97c629 100644
--- a/content/browser/renderer_host/input/input_router_impl_unittest.cc
+++ b/content/browser/renderer_host/input/input_router_impl_unittest.cc
@@ -276,6 +276,16 @@ class InputRouterImplTest : public testing::Test {
     return touch_event_id;
   }
 
+  // The TouchScrollStarted event doesn't need an ack from downstream, and is
+  // acked from within the TouchEventQueue to trigger its dequeuing. For this
+  // test, we send an artificial ack to get the same result.
+  void AckTouchScrollStartedNotification() {
+    ui::LatencyInfo latency_info;
+    input_router_->ProcessInputEventAck(
+        WebInputEvent::TouchScrollStarted, INPUT_EVENT_ACK_STATE_IGNORED,
+        latency_info, 0, InputRouterImpl::IGNORING_DISPOSITION);
+  }
+
   int PressTouchPoint(int x, int y) {
     return touch_event_.PressPoint(x, y);
   }
@@ -1101,6 +1111,11 @@ TEST_F(InputRouterImplTest, GestureTypesIgnoringAck) {
     EXPECT_EQ(1U, GetSentMessageCountAndResetSink());
     EXPECT_EQ(1U, ack_handler_->GetAndResetAckCount());
     EXPECT_EQ(0, client_->in_flight_event_count());
+
+    if (type == WebInputEvent::GestureScrollBegin) {
+      EXPECT_TRUE(HasPendingEvents());
+      AckTouchScrollStartedNotification();
+    }
     EXPECT_FALSE(HasPendingEvents());
   }
 }
@@ -1231,7 +1246,6 @@ TEST_F(InputRouterImplTest, GestureShowPressIsInOrder) {
   EXPECT_EQ(1U, GetSentMessageCountAndResetSink());
   EXPECT_EQ(1U, ack_handler_->GetAndResetAckCount());
 
-
   // GesturePinchBegin ignores its ack.
   SimulateGestureEvent(WebInputEvent::GesturePinchBegin,
                        blink::WebGestureDeviceTouchscreen);
@@ -1450,6 +1464,7 @@ TEST_F(InputRouterImplTest, TouchActionResetBeforeEventReachesRenderer) {
   EXPECT_EQ(1U, GetSentMessageCountAndResetSink());
   SendTouchEventACK(WebInputEvent::TouchEnd, INPUT_EVENT_ACK_STATE_CONSUMED,
                     touch_release_event_id2);
+  AckTouchScrollStartedNotification();
 }
 
 // Test that TouchActionFilter::ResetTouchAction is called when a new touch
@@ -1690,6 +1705,7 @@ TEST_F(InputRouterImplTest, InputFlushAfterFling) {
                        blink::WebGestureDeviceTouchscreen);
   SimulateGestureEvent(WebInputEvent::GestureFlingStart,
                        blink::WebGestureDeviceTouchscreen);
+  AckTouchScrollStartedNotification();
   EXPECT_TRUE(HasPendingEvents());
 
   // If the fling is unconsumed, the flush is complete.
@@ -1699,6 +1715,8 @@ TEST_F(InputRouterImplTest, InputFlushAfterFling) {
                        blink::WebGestureDeviceTouchscreen);
   SendInputEventACK(WebInputEvent::GestureFlingStart,
                     INPUT_EVENT_ACK_STATE_NOT_CONSUMED);
+  EXPECT_TRUE(HasPendingEvents());
+  AckTouchScrollStartedNotification();
   EXPECT_FALSE(HasPendingEvents());
   EXPECT_EQ(1U, GetAndResetDidFlushCount());
 
@@ -1726,6 +1744,7 @@ TEST_F(InputRouterImplTest, InputFlushAfterFling) {
                        blink::WebGestureDeviceTouchscreen);
   SimulateGestureEvent(WebInputEvent::GestureFlingStart,
                        blink::WebGestureDeviceTouchscreen);
+  AckTouchScrollStartedNotification();
   ASSERT_TRUE(HasPendingEvents());
   RequestNotificationWhenFlushed();
   EXPECT_EQ(0U, GetAndResetDidFlushCount());