[Mac] Fix issue where rubber-banding may get sporadically stuck.

content/browser/renderer_host/render_widget_host_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 "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/shared_memory.h"
 #include "base/timer.h"
 #include "content/browser/browser_thread_impl.h"
 #include "content/browser/renderer_host/backing_store.h"
@@ skipping 421 matching lines @@
 
   void SimulateWheelEvent(float dX, float dY, int modifiers) {
     WebMouseWheelEvent wheel_event;
     wheel_event.type = WebInputEvent::MouseWheel;
     wheel_event.deltaX = dX;
     wheel_event.deltaY = dY;
     wheel_event.modifiers = modifiers;
     host_->ForwardWheelEvent(wheel_event);
   }
 
+  void SimulateWheelEventWithPhase(WebMouseWheelEvent::Phase phase) {
+    WebMouseWheelEvent wheel_event;
+    wheel_event.type = WebInputEvent::MouseWheel;
+    wheel_event.phase = phase;
+    host_->ForwardWheelEvent(wheel_event);
+  }
+
   // Inject simple synthetic WebGestureEvent instances.
   void SimulateGestureEvent(WebInputEvent::Type type) {
     WebGestureEvent gesture_event;
     gesture_event.type = type;
     host_->ForwardGestureEvent(gesture_event);
   }
 
   void SimulateGestureScrollUpdateEvent(float dX, float dY, int modifiers) {
     WebGestureEvent gesture_event;
     gesture_event.type = WebInputEvent::GestureScrollUpdate;
@@ skipping 61 matching lines @@
     touch_event_.touches[index].state = WebKit::WebTouchPoint::StateMoved;
     touch_event_.type = WebInputEvent::TouchMove;
   }
 
   void ReleaseTouchPoint(int index) {
     CHECK(index >= 0 && index < touch_event_.touchesLengthCap);
     touch_event_.touches[index].state = WebKit::WebTouchPoint::StateReleased;
     touch_event_.type = WebInputEvent::TouchEnd;
   }
 
+  const WebInputEvent* GetInputEventFromMessage(const IPC::Message& message) {
+    PickleIterator iter(message);
+    const char* data;
+    int data_length;
+    if (!message.ReadData(&iter, &data, &data_length))
+      return NULL;
+    return reinterpret_cast<const WebInputEvent*>(data);
+  }
+
   MessageLoopForUI message_loop_;
 
   scoped_ptr<TestBrowserContext> browser_context_;
   RenderWidgetHostProcess* process_;  // Deleted automatically by the widget.
   scoped_ptr<MockRenderWidgetHostDelegate> delegate_;
   scoped_ptr<MockRenderWidgetHost> host_;
   scoped_ptr<TestView> view_;
   scoped_ptr<gfx::Screen> screen_;
 
  private:
@@ skipping 419 matching lines @@
   EXPECT_TRUE(process_->sink().GetUniqueMessageMatching(
                   ViewMsg_HandleInputEvent::ID));
   process_->sink().ClearMessages();
 
   // After the final ack, the queue should be empty.
   SendInputEventACK(WebInputEvent::MouseWheel, true);
   MessageLoop::current()->RunUntilIdle();
   EXPECT_EQ(0U, process_->sink().message_count());
 }
 
+TEST_F(RenderWidgetHostTest, CoalescesWheelEventsQueuedPhaseEndIsNotDropped) {
+  process_->sink().ClearMessages();
+
+  // Send an initial gesture begin and ACK it.
+  SimulateGestureEvent(WebInputEvent::GestureScrollBegin);
+  EXPECT_EQ(1U, process_->sink().message_count());
+  SendInputEventACK(WebInputEvent::GestureScrollBegin, true);
+  MessageLoop::current()->RunUntilIdle();
+
+  // Send a wheel event, should get sent directly.
+  SimulateWheelEvent(0, -5, 0);
+  EXPECT_EQ(2U, process_->sink().message_count());
+
+  // Send a wheel phase end event before an ACK is received for the previous
+  // wheel event, which should get queued.
+  SimulateWheelEventWithPhase(WebMouseWheelEvent::PhaseEnded);
+  EXPECT_EQ(2U, process_->sink().message_count());
+
+  // A gesture event should now result in the queued phase ended event being
+  // transmitted before it.
+  SimulateGestureEvent(WebInputEvent::GestureScrollEnd);
+  ASSERT_EQ(4U, process_->sink().message_count());
+
+  // Verify the events that were sent.
+  const WebInputEvent* input_event =
+      GetInputEventFromMessage(*process_->sink().GetMessageAt(2));
+  ASSERT_EQ(WebInputEvent::MouseWheel, input_event->type);
+  const WebMouseWheelEvent* wheel_event =
+      static_cast<const WebMouseWheelEvent*>(input_event);
+  ASSERT_EQ(WebMouseWheelEvent::PhaseEnded, wheel_event->phase);
+
+  input_event = GetInputEventFromMessage(*process_->sink().GetMessageAt(3));
+  EXPECT_EQ(WebInputEvent::GestureScrollEnd, input_event->type);
+}
+
 TEST_F(RenderWidgetHostTest, CoalescesGesturesEvents) {
   // Turn off debounce handling for test isolation.
   host_->set_debounce_interval_time_ms(0);
   process_->sink().ClearMessages();
   // Only GestureScrollUpdate events can be coalesced.
   // Simulate gesture events.
 
   // Sent.
   SimulateGestureEvent(WebInputEvent::GestureScrollBegin);
 
@@ skipping 821 matching lines @@
   process_->InitUpdateRectParams(&params);
   params.scale_factor = params.scale_factor * 2;
 
   EXPECT_EQ(0, process_->bad_msg_count());
   host_->OnMsgUpdateRect(params);
   EXPECT_EQ(1, process_->bad_msg_count());
 }
 #endif
 
 }  // namespace content