Desktop Aura: Allow tab drags out of window.

ui/base/cocoa/events_mac.mm

 // 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 <Cocoa/Cocoa.h>
 
 #include "ui/base/events.h"
 
 #include "base/logging.h"
 #include "base/time.h"
@@ skipping 110 matching lines @@
   // would be to hit-test the view of the event and use the found view's
   // coordinate system.  Currently there is no need for this generality, and
   // speed is preferred.  Flipped views are not suppported.
   DCHECK([[window contentView] isFlipped] == NO);
   location = [[window contentView] convertPoint:location fromView:nil];
   location.y = [[window contentView] bounds].size.height - location.y;
 
   return gfx::Point(NSPointToCGPoint(location));
 }
 
+gfx::Point EventSystemLocationFromNative(
+    const base::NativeEvent& native_event) {
+  // TODO(port): Needs to always return screen position here. Returning normal
+  // origin for now since that's obviously wrong.
+  return gfx::Point(0, 0);
+}
+
 KeyboardCode KeyboardCodeFromNative(const base::NativeEvent& native_event) {
   return ui::KeyboardCodeFromNSEvent(native_event);
 }
 
 bool IsMouseEvent(const base::NativeEvent& native_event) {
   EventType type = EventTypeFromNative(native_event);
   return type == ET_MOUSE_PRESSED ||
          type == ET_MOUSE_DRAGGED ||
          type == ET_MOUSE_RELEASED ||
          type == ET_MOUSE_MOVED ||
@@ skipping 48 matching lines @@
                        modifierFlags:0
                            timestamp:[NSDate timeIntervalSinceReferenceDate]
                         windowNumber:0
                              context:nil
                              subtype:0
                                data1:0
                                data2:0];
 }
 
 }  // namespace ui