Implement compositor thread VSync aligned event queue

ui/events/blink/blink_event_util.h

 // Copyright 2015 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.
 
 #ifndef UI_EVENTS_BLINK_BLINK_EVENT_UTIL_H_
 #define UI_EVENTS_BLINK_BLINK_EVENT_UTIL_H_
 
 #include <memory>
 
 #include "third_party/WebKit/public/platform/WebInputEvent.h"
 #include "ui/events/gesture_detection/motion_event.h"
 
 namespace blink {
 class WebGestureEvent;
 class WebInputEvent;
 class WebTouchEvent;
 }
 
 namespace gfx {
 class PointF;
 class Vector2d;
 }
 
 namespace ui {
 enum class DomCode;
 struct GestureEventData;
 struct GestureEventDetails;
 class MotionEvent;
 
+bool CanCoalesce(const blink::WebInputEvent& event_to_coalesce,
+                 const blink::WebInputEvent& event);
+
+void Coalesce(const blink::WebInputEvent& event_to_coalesce,
+              blink::WebInputEvent* event);
+
 blink::WebTouchEvent CreateWebTouchEventFromMotionEvent(
     const MotionEvent& event,
     bool may_cause_scrolling);
 
 blink::WebGestureEvent CreateWebGestureEvent(const GestureEventDetails& details,
                                              base::TimeTicks timestamp,
                                              const gfx::PointF& location,
                                              const gfx::PointF& raw_location,
                                              int flags,
                                              uint32_t unique_touch_event_id);
@@ skipping 27 matching lines @@
     float orientation_rad,
     float tilt_rad,
     int android_buttons_changed,
     int tool_type);
 
 int WebEventModifiersToEventFlags(int modifiers);
 
 blink::WebInputEvent::Modifiers DomCodeToWebInputEventModifiers(
     ui::DomCode code);
 
+bool IsGestureScollOrPinch(blink::WebInputEvent::Type);
+
+bool IsContinuousGestureEvent(blink::WebInputEvent::Type);
+
 }  // namespace ui
 
 #endif  // UI_EVENTS_BLINK_BLINK_EVENT_UTIL_H_