Coalesce async touch move events until the ack back from render

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 f56991892266ceeca85f3a84ec97a7d01d5d3f37..58f99f48fcac1cdd603f5d21a779c1c71190ff99 100644
--- a/content/browser/renderer_host/input/input_router_impl_unittest.cc
+++ b/content/browser/renderer_host/input/input_router_impl_unittest.cc
@@ -155,6 +155,8 @@ class InputRouterImplTest : public testing::Test {
                                             config_));
     client_->set_input_router(input_router());
     ack_handler_->set_input_router(input_router());
+    sent_events_ids_.clear();
+    all_sent_events_ids_.clear();
   }
 
   void TearDown() override {
@@ -250,6 +252,7 @@ class InputRouterImplTest : public testing::Test {
   void SendTouchEvent() {
     input_router_->SendTouchEvent(TouchEventWithLatencyInfo(touch_event_));
     touch_event_.ResetPoints();
+    SetLastEventID();
   }
 
   int PressTouchPoint(int x, int y) {
@@ -273,7 +276,13 @@ class InputRouterImplTest : public testing::Test {
     InputHostMsg_HandleInputEvent_ACK_Params ack;
     ack.type = type;
     ack.state = ack_result;
+    if (WebInputEvent::isTouchEventType(type)) {
+      DCHECK(!sent_events_ids_.empty());
+      ack.unique_touch_event_id = sent_events_ids_.front();
+      sent_events_ids_.pop_front();
+    }
     input_router_->OnMessageReceived(InputHostMsg_HandleInputEvent_ACK(0, ack));
+    SetLastEventID();
   }
 
   void NotifyDidStopFlinging() {
@@ -320,6 +329,22 @@ class InputRouterImplTest : public testing::Test {
     return count;
   }
 
+  bool TouchEventCancelable() { return touch_event_.cancelable; }
+
+  void SetLastEventID() {
+    size_t count = process_->sink().message_count();
+    for (size_t i = 0; i < count; ++i) {
+      const WebInputEvent* input_event =
+          GetInputEventFromMessage(*process_->sink().GetMessageAt(i));
+      uint32 id = WebInputEventTraits::GetUniqueTouchEventId(*input_event);
+      if (id != 0 &&
+          all_sent_events_ids_.find(id) == all_sent_events_ids_.end()) {
+        sent_events_ids_.push_back(id);
+        all_sent_events_ids_.insert(id);
+      }
+    }
+  }
+
   static void RunTasksAndWait(base::TimeDelta delay) {
     base::MessageLoop::current()->PostDelayedTask(
         FROM_HERE, base::MessageLoop::QuitClosure(), delay);
@@ -337,6 +362,8 @@ class InputRouterImplTest : public testing::Test {
   SyntheticWebTouchEvent touch_event_;
 
   scoped_ptr<TestBrowserContext> browser_context_;
+  std::deque<uint32> sent_events_ids_;
+  std::set<uint32> all_sent_events_ids_;
 };
 
 TEST_F(InputRouterImplTest, CoalescesRangeSelection) {
@@ -961,11 +988,11 @@ TEST_F(InputRouterImplTest, UnhandledWheelEvent) {
 TEST_F(InputRouterImplTest, TouchTypesIgnoringAck) {
   OnHasTouchEventHandlers(true);
   // Only acks for TouchCancel should always be ignored.
-  ASSERT_FALSE(WebInputEventTraits::IgnoresAckDisposition(
+  ASSERT_TRUE(WebInputEventTraits::WillReceiveAckFromRenderer(
       GetEventWithType(WebInputEvent::TouchStart)));
-  ASSERT_FALSE(WebInputEventTraits::IgnoresAckDisposition(
+  ASSERT_TRUE(WebInputEventTraits::WillReceiveAckFromRenderer(
       GetEventWithType(WebInputEvent::TouchMove)));
-  ASSERT_FALSE(WebInputEventTraits::IgnoresAckDisposition(
+  ASSERT_TRUE(WebInputEventTraits::WillReceiveAckFromRenderer(
       GetEventWithType(WebInputEvent::TouchEnd)));
 
   // Precede the TouchCancel with an appropriate TouchStart;
@@ -1024,7 +1051,8 @@ TEST_F(InputRouterImplTest, GestureTypesIgnoringAck) {
   for (size_t i = 0; i < arraysize(eventTypes); ++i) {
     WebInputEvent::Type type = eventTypes[i];
     SCOPED_TRACE(WebInputEventTraits::GetName(type));
-    if (!WebInputEventTraits::IgnoresAckDisposition(GetEventWithType(type))) {
+    if (WebInputEventTraits::WillReceiveAckFromRenderer(
+            GetEventWithType(type))) {
       SimulateGestureEvent(type, blink::WebGestureDeviceTouchscreen);
       EXPECT_EQ(1U, GetSentMessageCountAndResetSink());
       EXPECT_EQ(0U, ack_handler_->GetAndResetAckCount());
@@ -1063,8 +1091,9 @@ TEST_F(InputRouterImplTest, MouseTypesIgnoringAck) {
   for (int i = start_type; i <= end_type; ++i) {
     WebInputEvent::Type type = static_cast<WebInputEvent::Type>(i);
     int expected_in_flight_event_count =
-        WebInputEventTraits::IgnoresAckDisposition(GetEventWithType(type)) ? 0
-                                                                           : 1;
+        !WebInputEventTraits::WillReceiveAckFromRenderer(GetEventWithType(type))
+            ? 0
+            : 1;
 
     // Note: Mouse event acks are never forwarded to the ack handler, so the key
     // result here is that ignored ack types don't affect the in-flight count.
@@ -1082,7 +1111,7 @@ TEST_F(InputRouterImplTest, MouseTypesIgnoringAck) {
 }
 
 // Guard against breaking changes to the list of ignored event ack types in
-// |WebInputEventTraits::IgnoresAckDisposition|.
+// |WebInputEventTraits::WillReceiveAckFromRenderer|.
 TEST_F(InputRouterImplTest, RequiredEventAckTypes) {
   const WebInputEvent::Type kRequiredEventAckTypes[] = {
     WebInputEvent::MouseMove,
@@ -1100,7 +1129,7 @@ TEST_F(InputRouterImplTest, RequiredEventAckTypes) {
   };
   for (size_t i = 0; i < arraysize(kRequiredEventAckTypes); ++i) {
     const WebInputEvent::Type required_ack_type = kRequiredEventAckTypes[i];
-    EXPECT_FALSE(WebInputEventTraits::IgnoresAckDisposition(
+    ASSERT_TRUE(WebInputEventTraits::WillReceiveAckFromRenderer(
         GetEventWithType(required_ack_type)));
   }
 }
@@ -1518,7 +1547,7 @@ TEST_F(InputRouterImplTest, DoubleTapGestureDependsOnFirstTap) {
                        blink::WebGestureDeviceTouchscreen);
   EXPECT_EQ(1U, GetSentMessageCountAndResetSink());
   // This test will become invalid if GestureTap stops requiring an ack.
-  ASSERT_FALSE(WebInputEventTraits::IgnoresAckDisposition(
+  ASSERT_TRUE(WebInputEventTraits::WillReceiveAckFromRenderer(
       GetEventWithType(WebInputEvent::GestureTap)));
   EXPECT_EQ(2, client_->in_flight_event_count());
   SendInputEventACK(WebInputEvent::GestureTap,
@@ -1546,7 +1575,7 @@ TEST_F(InputRouterImplTest, DoubleTapGestureDependsOnFirstTap) {
   SimulateGestureEvent(WebInputEvent::GestureDoubleTap,
                        blink::WebGestureDeviceTouchscreen);
   // This test will become invalid if GestureDoubleTap stops requiring an ack.
-  ASSERT_FALSE(WebInputEventTraits::IgnoresAckDisposition(
+  ASSERT_TRUE(WebInputEventTraits::WillReceiveAckFromRenderer(
       GetEventWithType(WebInputEvent::GestureDoubleTap)));
   EXPECT_EQ(1, client_->in_flight_event_count());
   SendInputEventACK(WebInputEvent::GestureTap, INPUT_EVENT_ACK_STATE_CONSUMED);