Coalesce async touch move events until the ack back from render

content/browser/renderer_host/render_widget_host_view_aura_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_view_aura.h"
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/shared_memory.h"
@@ skipping 428 matching lines @@
     // destroyed. The correct fix would be to have ObserverListThreadSafe look
     // up the proper message loop every time (see crbug.com/443824.)
     RendererFrameManager::GetInstance()->OnMemoryPressure(level);
   }
 
   void SendInputEventACK(WebInputEvent::Type type,
       InputEventAckState ack_result) {
     InputHostMsg_HandleInputEvent_ACK_Params ack;
     ack.type = type;
     ack.state = ack_result;
+    if (WebInputEvent::isTouchEventType(type))
+      ack.unique_touch_event_id = last_send_event_id_;
     InputHostMsg_HandleInputEvent_ACK response(0, ack);
     widget_host_->OnMessageReceived(response);
   }
 
   size_t GetSentMessageCountAndResetSink() {
     size_t count = sink_->message_count();
     sink_->ClearMessages();
     return count;
   }
 
   void AckLastSentInputEventIfNecessary(InputEventAckState ack_result) {
     if (!sink_->message_count())
       return;
 
     InputMsg_HandleInputEvent::Param params;
     if (!InputMsg_HandleInputEvent::Read(
             sink_->GetMessageAt(sink_->message_count() - 1), &params)) {
       return;
     }
 
-    if (WebInputEventTraits::IgnoresAckDisposition(*get<0>(params)))
+    if (!WebInputEventTraits::WillReceiveAckFromRenderer(*get<0>(params)))
       return;
 
     SendInputEventACK(get<0>(params)->type, ack_result);
   }
 
+  void SetLastSentEventID(uint32 event_id) { last_send_event_id_ = event_id; }
+
  protected:
   // If true, then calls RWH::Shutdown() instead of deleting RWH.
   bool widget_host_uses_shutdown_to_destroy_;
 
   bool is_guest_view_hack_;
 
   base::MessageLoopForUI message_loop_;
   BrowserThreadImpl browser_thread_for_ui_;
   scoped_ptr<aura::test::AuraTestHelper> aura_test_helper_;
   scoped_ptr<BrowserContext> browser_context_;
   MockRenderWidgetHostDelegate delegate_;
   MockRenderProcessHost* process_host_;
 
   // Tests should set these to NULL if they've already triggered their
   // destruction.
   RenderWidgetHostImpl* parent_host_;
   RenderWidgetHostViewAura* parent_view_;
 
   // Tests should set these to NULL if they've already triggered their
   // destruction.
   RenderWidgetHostImpl* widget_host_;
   FakeRenderWidgetHostViewAura* view_;
 
   IPC::TestSink* sink_;
 
+  uint32 last_send_event_id_;

[jdduke (slow), 2015/05/01 19:11:09]

Nit: last_sent

[lanwei, 2015/05/07 04:11:37]

Done.

+
  private:
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewAuraTest);
 };
 
 // Helper class to instantiate RenderWidgetHostViewGuest which is backed
 // by an aura platform view.
 class RenderWidgetHostViewGuestAuraTest : public RenderWidgetHostViewAuraTest {
  public:
   RenderWidgetHostViewGuestAuraTest() {
     // Use RWH::Shutdown to destroy RWH, instead of deleting.
@@ skipping 182 matching lines @@
     return view_->overscroll_controller()->overscroll_delta_y_;
   }
 
   TestOverscrollDelegate* overscroll_delegate() {
     return overscroll_delegate_.get();
   }
 
   void SendTouchEvent() {
     widget_host_->ForwardTouchEventWithLatencyInfo(touch_event_,
                                                    ui::LatencyInfo());
+    last_send_event_id_ = touch_event_.uniqueTouchEventId;

[jdduke (slow), 2015/05/01 19:11:09]

Hmm, but what if touches are still in the queue? Or do we not test that? This
method gets called *before* a touch is sent to the queue, so if we then ack an
event that has already been sent, we're acking the wrong event.

     touch_event_.ResetPoints();
   }
 
   void PressTouchPoint(int x, int y) {
     touch_event_.PressPoint(x, y);
     SendTouchEvent();
   }
 
   void MoveTouchPoint(int index, int x, int y) {
     touch_event_.MovePoint(index, x, y);
@@ skipping 2593 matching lines @@
 // lose track of the number of acks required.
 TEST_F(RenderWidgetHostViewAuraTest, CorrectNumberOfAcksAreDispatched) {
   view_->InitAsFullscreen(parent_view_);
   view_->Show();
   view_->UseFakeDispatcher();
 
   ui::TouchEvent press1(
       ui::ET_TOUCH_PRESSED, gfx::Point(30, 30), 0, ui::EventTimeForNow());
 
   view_->OnTouchEvent(&press1);
+  SetLastSentEventID(press1.unique_event_id());
   SendInputEventACK(blink::WebInputEvent::TouchStart,
                     INPUT_EVENT_ACK_STATE_CONSUMED);
 
   ui::TouchEvent press2(
       ui::ET_TOUCH_PRESSED, gfx::Point(20, 20), 1, ui::EventTimeForNow());
   view_->OnTouchEvent(&press2);
+  SetLastSentEventID(press2.unique_event_id());
   SendInputEventACK(blink::WebInputEvent::TouchStart,
                     INPUT_EVENT_ACK_STATE_CONSUMED);
 
   EXPECT_EQ(2U, view_->dispatcher_->processed_touch_event_count());
 }
 
 // Tests that the scroll deltas stored within the overscroll controller get
 // reset at the end of the overscroll gesture even if the overscroll threshold
 // isn't surpassed and the overscroll mode stays OVERSCROLL_NONE.
 TEST_F(RenderWidgetHostViewAuraOverscrollTest, ScrollDeltasResetOnEnd) {
@@ skipping 32 matching lines @@
                     INPUT_EVENT_ACK_STATE_NOT_CONSUMED);
   EXPECT_EQ(OVERSCROLL_NONE, overscroll_mode());
   EXPECT_EQ(15.f, overscroll_delta_x());
   EXPECT_EQ(-5.f, overscroll_delta_y());
   SimulateGestureFlingStartEvent(0.f, 0.1f, blink::WebGestureDeviceTouchpad);
   EXPECT_EQ(0.f, overscroll_delta_x());
   EXPECT_EQ(0.f, overscroll_delta_y());
 }
 
 }  // namespace content