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 448 matching lines @@
   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);
   }
 
  protected:
   // If true, then calls RWH::Shutdown() instead of deleting RWH.
   bool widget_host_uses_shutdown_to_destroy_;
 
   bool is_guest_view_hack_;
@@ skipping 2883 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