MacViews: Implement basic NSEvent -> ui::Event conversion for Mac

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/event_types.h"
 #include "ui/events/event_constants.h"
 #include "ui/events/keycodes/keyboard_codes.h"
@@ skipping 66 matching lines @@
     const base::NativeEvent& native_event);
 
 // Returns the flags of the button that changed during a press/release.
 EVENTS_EXPORT int GetChangedMouseButtonFlagsFromNative(
     const base::NativeEvent& native_event);
 
 // Gets the mouse wheel offsets from a native event.
 EVENTS_EXPORT gfx::Vector2d GetMouseWheelOffset(
     const base::NativeEvent& native_event);
 
+// Returns a copy of |native_event|. Depending on the platform, this copy may
+// need to be deleted with ReleaseCopiedNativeEvent().
+base::NativeEvent CopyNativeEvent(
+    const base::NativeEvent& native_event);
+
+// Delete a |native_event| previously created by CopyNativeEvent().
+void ReleaseCopiedNativeEvent(
+    const base::NativeEvent& native_event);
+
 // Gets the touch id from a native event.
 EVENTS_EXPORT int GetTouchId(const base::NativeEvent& native_event);
 
 // Clear the touch id from bookkeeping if it is a release/cancel event.
 EVENTS_EXPORT void ClearTouchIdIfReleased(
     const base::NativeEvent& native_event);
 
 // Gets the radius along the X/Y axis from a native event. Default is 1.0.
 EVENTS_EXPORT float GetTouchRadiusX(const base::NativeEvent& native_event);
 EVENTS_EXPORT float GetTouchRadiusY(const base::NativeEvent& native_event);
@@ skipping 50 matching lines @@
 EVENTS_EXPORT uint16 GetScanCodeFromLParam(LPARAM lParam);
 EVENTS_EXPORT LPARAM GetLParamFromScanCode(uint16 scan_code);
 #endif
 
 // Registers a custom event type.
 EVENTS_EXPORT int RegisterCustomEventType();
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_EVENT_UTILS_H_