SelectionOwner: add support for TIMESTAMP target

ui/base/x/selection_owner.h

 // Copyright (c) 2013 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_BASE_X_SELECTION_OWNER_H_
 #define UI_BASE_X_SELECTION_OWNER_H_
 
 #include <stddef.h>
 
 #include <vector>
@@ skipping 101 matching lines @@
   std::vector<IncrementalTransfer>::iterator FindIncrementalTransferForEvent(
       const XEvent& event);
 
   // Our X11 state.
   XDisplay* x_display_;
   XID x_window_;
 
   // The X11 selection that this instance communicates on.
   XAtom selection_name_;
 
+  // The time that this instance took ownership of its selection.
+  Time acquired_selection_timestamp_;
+
   // The maximum size of data we can put in XChangeProperty().
   size_t max_request_size_;
 
   // The data we are currently serving.
   SelectionFormatMap format_map_;
 
   std::vector<IncrementalTransfer> incremental_transfers_;
 
   // Used to abort stale incremental data transfers.
   base::RepeatingTimer incremental_transfer_abort_timer_;
 
   X11AtomCache atom_cache_;
 
   DISALLOW_COPY_AND_ASSIGN(SelectionOwner);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_X_SELECTION_OWNER_H_