exo: Fix multi-display hardware cursor

ui/aura/client/cursor_client.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_AURA_CLIENT_CURSOR_CLIENT_H_
 #define UI_AURA_CLIENT_CURSOR_CLIENT_H_
 
 #include "base/strings/string16.h"
 #include "ui/aura/aura_export.h"
 #include "ui/base/cursor/cursor.h"
@@ skipping 43 matching lines @@
 
   // Makes mouse events stop being sent and hides the cursor if it is visible.
   virtual void DisableMouseEvents() = 0;
 
   // Returns true if mouse events are enabled.
   virtual bool IsMouseEventsEnabled() const = 0;
 
   // Sets the display for the cursor.
   virtual void SetDisplay(const display::Display& display) = 0;
 
+  // Returns the display where the cursor is located.
+  virtual const display::Display& GetDisplay() const = 0;
+
   // Locks the cursor change. The cursor type, cursor visibility, and mouse
   // events enable state never change as long as lock is held by anyone.
   virtual void LockCursor() = 0;
 
   // Unlocks the cursor change. If all the locks are released, the cursor type,
   // cursor visibility, and mouse events enable state are restored to the ones
   // set by the lastest call of SetCursor, ShowCursor/HideCursor, and
   // EnableMouseEvents/DisableMouseEvents.
   virtual void UnlockCursor() = 0;
 
@@ skipping 13 matching lines @@
 
 // Sets/Gets the activation client for the specified window.
 AURA_EXPORT void SetCursorClient(Window* window,
                                  CursorClient* client);
 AURA_EXPORT CursorClient* GetCursorClient(Window* window);
 
 }  // namespace client
 }  // namespace aura
 
 #endif  // UI_AURA_CLIENT_CURSOR_CLIENT_H_