Signal input flush when all flings have terminated

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 ec62671036c9d1bf5dce65f94c33da868dac7cc9..072359a2ed5f4d5726931c1ad87704980f1f02df 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 +276,10 @@ class InputRouterImplTest : public testing::Test {
     input_router_->OnMessageReceived(InputHostMsg_HandleInputEvent_ACK(0, ack));
   }
 
+  void NotifyDidStopFlinging() {
+    input_router_->OnMessageReceived(InputHostMsg_DidStopFlinging(0));
+  }
+
   InputRouterImpl* input_router() const {
     return input_router_.get();
   }
@@ -288,8 +292,8 @@ class InputRouterImplTest : public testing::Test {
     return input_router()->touch_event_queue_.IsAckTimeoutEnabled();
   }
 
-  void Flush() const {
-    return input_router_->Flush();
+  void RequestNotificationWhenFlushed() const {
+    return input_router_->RequestNotificationWhenFlushed();
   }
 
   size_t GetAndResetDidFlushCount() {
@@ -1545,7 +1549,7 @@ TEST_F(InputRouterImplTest, InputFlush) {
   EXPECT_FALSE(HasPendingEvents());
 
   // Flushing an empty router should immediately trigger DidFlush.
-  Flush();
+  RequestNotificationWhenFlushed();
   EXPECT_EQ(1U, GetAndResetDidFlushCount());
   EXPECT_FALSE(HasPendingEvents());
 
@@ -1556,7 +1560,7 @@ TEST_F(InputRouterImplTest, InputFlush) {
   EXPECT_TRUE(HasPendingEvents());
 
   // DidFlush should be called only after the event is ack'ed.
-  Flush();
+  RequestNotificationWhenFlushed();
   EXPECT_EQ(0U, GetAndResetDidFlushCount());
   SendInputEventACK(WebInputEvent::TouchStart,
                     INPUT_EVENT_ACK_STATE_NOT_CONSUMED);
@@ -1575,11 +1579,11 @@ TEST_F(InputRouterImplTest, InputFlush) {
                        blink::WebGestureDeviceTouchscreen);
   SimulateGestureEvent(WebInputEvent::GesturePinchUpdate,
                        blink::WebGestureDeviceTouchscreen);
-  Flush();
+  RequestNotificationWhenFlushed();
   EXPECT_EQ(0U, GetAndResetDidFlushCount());
 
   // Repeated flush calls should have no effect.
-  Flush();
+  RequestNotificationWhenFlushed();
   EXPECT_EQ(0U, GetAndResetDidFlushCount());
 
   // There are still pending gestures.
@@ -1601,6 +1605,47 @@ TEST_F(InputRouterImplTest, InputFlush) {
   EXPECT_FALSE(HasPendingEvents());
 }
 
+// Test that the router will call the client's |DidFlush| after all fling
+// animations have completed.
+TEST_F(InputRouterImplTest, InputFlushAfterFling) {
+  EXPECT_FALSE(HasPendingEvents());
+
+  // Simulate a fling.
+  SimulateGestureEvent(WebInputEvent::GestureScrollBegin,
+                       blink::WebGestureDeviceTouchscreen);
+  SimulateGestureEvent(WebInputEvent::GestureFlingStart,
+                       blink::WebGestureDeviceTouchscreen);
+  EXPECT_TRUE(HasPendingEvents());
+
+  // If the fling is unconsumed, the flush is complete.
+  RequestNotificationWhenFlushed();
+  EXPECT_EQ(0U, GetAndResetDidFlushCount());
+  SimulateGestureEvent(WebInputEvent::GestureScrollBegin,
+                       blink::WebGestureDeviceTouchscreen);
+  SendInputEventACK(WebInputEvent::GestureFlingStart,
+                    INPUT_EVENT_ACK_STATE_NOT_CONSUMED);
+  EXPECT_FALSE(HasPendingEvents());
+  EXPECT_EQ(1U, GetAndResetDidFlushCount());
+
+  // Simulate a second fling.
+  SimulateGestureEvent(WebInputEvent::GestureFlingStart,
+                       blink::WebGestureDeviceTouchscreen);
+  EXPECT_TRUE(HasPendingEvents());
+
+  // If the fling is consumed, the flush is complete only when the renderer
+  // reports that is has ended.
+  RequestNotificationWhenFlushed();
+  EXPECT_EQ(0U, GetAndResetDidFlushCount());
+  SendInputEventACK(WebInputEvent::GestureFlingStart,
+                    INPUT_EVENT_ACK_STATE_CONSUMED);
+  EXPECT_TRUE(HasPendingEvents());
+  EXPECT_EQ(0U, GetAndResetDidFlushCount());
+
+  // The fling end notification should signal that the router is flushed.
+  NotifyDidStopFlinging();
+  EXPECT_EQ(1U, GetAndResetDidFlushCount());
+}
+
 // Test that GesturePinchUpdate is handled specially for trackpad
 TEST_F(InputRouterImplTest, TouchpadPinchUpdate) {
   // GesturePinchUpdate for trackpad sends synthetic wheel events.