Set the unique_event_id when converting from TouchEvent to WebTouchEvent

ui/events/event_utils.h

 // 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.
 
 #ifndef UI_EVENTS_EVENT_UTILS_H_
 #define UI_EVENTS_EVENT_UTILS_H_
 
 #include "base/basictypes.h"
 #include "base/event_types.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 10 matching lines @@
 
 namespace gfx {
 class Point;
 class Vector2d;
 }
 
 namespace base {
 class TimeDelta;
 }
 
+// Common functions to be used for all platforms except Android.
 namespace ui {
 
 class Event;
 class MouseEvent;
 enum class DomCode;
 
 // Updates the list of devices for cached properties.
 EVENTS_EXPORT void UpdateDeviceList();
 
 // Returns a ui::Event wrapping a native event. Ownership of the returned value
@@ skipping 131 matching lines @@
 // Update the native X11 event to correspond to the new button flags.
 EVENTS_EXPORT void UpdateX11EventForChangedButtonFlags(MouseEvent* event);
 #endif
 
 // Registers a custom event type.
 EVENTS_EXPORT int RegisterCustomEventType();
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_EVENT_UTILS_H_