Refactor CopyNativeEvent and add events_mac.mm to start implementing stubs

ui/events/win/events_win.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 <windowsx.h>
 
 #include "ui/events/event_constants.h"
 
 #include "base/logging.h"
 #include "base/time/time.h"
@@ skipping 261 matching lines @@
 }
 
 gfx::Vector2d GetMouseWheelOffset(const base::NativeEvent& native_event) {
   DCHECK(native_event.message == WM_MOUSEWHEEL ||
          native_event.message == WM_MOUSEHWHEEL);
   if (native_event.message == WM_MOUSEWHEEL)
     return gfx::Vector2d(0, GET_WHEEL_DELTA_WPARAM(native_event.wParam));
   return gfx::Vector2d(GET_WHEEL_DELTA_WPARAM(native_event.wParam), 0);
 }
 
+base::NativeEvent CopyNativeEvent(const base::NativeEvent& event) {
+  return event;
+}
+
+void ReleaseCopiedNativeEvent(const base::NativeEvent& event) {}
+
 void ClearTouchIdIfReleased(const base::NativeEvent& xev) {
   NOTIMPLEMENTED();
 }
 
 int GetTouchId(const base::NativeEvent& xev) {
   NOTIMPLEMENTED();
   return 0;
 }
 
 float GetTouchRadiusX(const base::NativeEvent& native_event) {
@@ skipping 112 matching lines @@
 }
 
 LPARAM GetLParamFromScanCode(uint16 scan_code) {
   LPARAM l_param = static_cast<LPARAM>(scan_code & 0x00FF) << 16;
   if ((scan_code & 0xE000) == 0xE000)
     l_param |= (1 << 24);
   return l_param;
 }
 
 }  // namespace ui