Coalesce async touch move events until the ack back from render

content/browser/renderer_host/render_widget_host_view_mac_unittest.mm

 // 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_mac.h"
 
 #include <Cocoa/Cocoa.h>
 
 #include "base/mac/mac_util.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
@@ skipping 692 matching lines @@
   MockRenderWidgetHostImpl* host = new MockRenderWidgetHostImpl(
       &delegate, process_host, MSG_ROUTING_NONE);
   RenderWidgetHostViewMac* view = new RenderWidgetHostViewMac(host, false);
 
   // Send an initial wheel event with NSEventPhaseBegan to the view.
   NSEvent* event1 = MockScrollWheelEventWithPhase(@selector(phaseBegan), 0);
   [view->cocoa_view() scrollWheel:event1];
   ASSERT_EQ(1U, process_host->sink().message_count());
 
   // Send an ACK for the first wheel event, so that the queue will be flushed.
-  InputHostMsg_HandleInputEvent_ACK_Params ack;
-  ack.type = blink::WebInputEvent::MouseWheel;
-  ack.state = INPUT_EVENT_ACK_STATE_CONSUMED;
+  InputEventAck ack(blink::WebInputEvent::MouseWheel,
+                    INPUT_EVENT_ACK_STATE_CONSUMED);
   scoped_ptr<IPC::Message> response(
       new InputHostMsg_HandleInputEvent_ACK(0, ack));
   host->OnMessageReceived(*response);
 
   // Post the NSEventPhaseEnded wheel event to NSApp and check whether the
   // render view receives it.
   NSEvent* event2 = MockScrollWheelEventWithPhase(@selector(phaseEnded), 0);
   [NSApp postEvent:event2 atStart:NO];
   base::MessageLoop::current()->RunUntilIdle();
   ASSERT_EQ(2U, process_host->sink().message_count());
@@ skipping 23 matching lines @@
       [[MockRenderWidgetHostViewMacDelegate alloc] init]);
   view->SetDelegate(view_delegate.get());
 
   // Send an initial wheel event for scrolling by 3 lines.
   NSEvent* event1 = MockScrollWheelEventWithPhase(@selector(phaseBegan), 3);
   [view->cocoa_view() scrollWheel:event1];
   ASSERT_EQ(1U, process_host->sink().message_count());
   process_host->sink().ClearMessages();
 
   // Indicate that the wheel event was unhandled.
-  InputHostMsg_HandleInputEvent_ACK_Params unhandled_ack;
-  unhandled_ack.type = blink::WebInputEvent::MouseWheel;
-  unhandled_ack.state = INPUT_EVENT_ACK_STATE_NOT_CONSUMED;
+  InputEventAck unhandled_ack(blink::WebInputEvent::MouseWheel,
+                              INPUT_EVENT_ACK_STATE_NOT_CONSUMED);
   scoped_ptr<IPC::Message> response1(
       new InputHostMsg_HandleInputEvent_ACK(0, unhandled_ack));
   host->OnMessageReceived(*response1);
 
   // Check that the view delegate got an unhandled wheel event.
   ASSERT_EQ(YES, view_delegate.get().unhandledWheelEventReceived);
   view_delegate.get().unhandledWheelEventReceived = NO;
 
   // Send another wheel event, this time for scrolling by 0 lines (empty event).
   NSEvent* event2 = MockScrollWheelEventWithPhase(@selector(phaseChanged), 0);
@@ skipping 104 matching lines @@
   // out |OnMessageReceived()|.
   TestBrowserContext browser_context;
   MockRenderProcessHost* process_host =
       new MockRenderProcessHost(&browser_context);
   MockRenderWidgetHostDelegate delegate;
   MockRenderWidgetHostImpl* host = new MockRenderWidgetHostImpl(
       &delegate, process_host, MSG_ROUTING_NONE);
   RenderWidgetHostViewMac* view = new RenderWidgetHostViewMac(host, false);
 
   // We'll use this IPC message to ack events.
-  InputHostMsg_HandleInputEvent_ACK_Params ack;
-  ack.type = blink::WebInputEvent::GesturePinchUpdate;
-  ack.state = INPUT_EVENT_ACK_STATE_CONSUMED;
+  InputEventAck ack(blink::WebInputEvent::GesturePinchUpdate,
+                    INPUT_EVENT_ACK_STATE_CONSUMED);
   scoped_ptr<IPC::Message> response(
       new InputHostMsg_HandleInputEvent_ACK(0, ack));
 
   // Do a gesture that crosses the threshold.
   {
     NSEvent* pinchBeginEvent =
         MockGestureEvent(NSEventTypeBeginGesture, 100.1, 0);
     NSEvent* pinchUpdateEvents[3] = {
         MockGestureEvent(NSEventTypeMagnify, 100.2, 0.25),
         MockGestureEvent(NSEventTypeMagnify, 100.3, 0.25),
@@ skipping 75 matching lines @@
 
     process_host->sink().ClearMessages();
   }
 
   // Clean up.
   host->Shutdown();
 }
 
 
 }  // namespace content