linux_aura: Redo how memory is handled in clipboard/drag code.

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 <X11/Xlib.h>
 
 // Get rid of a macro from Xlib.h that conflicts with Aura's RootWindow class.
 #undef RootWindow
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "ui/base/ui_export.h"
+#include "ui/base/x/selection_utils.h"
 #include "ui/base/x/x11_atom_cache.h"
 
 namespace ui {
 
-class SelectionFormatMap;
-
 // Owns a specific X11 selection on an X window.
 //
 // The selection owner object keeps track of which xwindow is the current
 // owner, and when its |xwindow_|, offers different data types to other
 // processes.
 class UI_EXPORT SelectionOwner {
  public:
   SelectionOwner(Display* xdisplay,
                  ::Window xwindow,
                  ::Atom selection_name);
   ~SelectionOwner();
 
   // Returns the current selection data. Useful for fast paths.
-  SelectionFormatMap* selection_format_map() { return selection_data_.get(); }
+  const SelectionFormatMap& selection_format_map() { return format_map_; }
 
   // Retrieves a list of types we're offering.
   void RetrieveTargets(std::vector<Atom>* targets);
 
   // Attempts to take ownership of the selection. If we're successful, present
   // |data| to other windows.
-  void TakeOwnershipOfSelection(scoped_ptr<SelectionFormatMap> data);
+  void TakeOwnershipOfSelection(const SelectionFormatMap& data);
 
   // Releases the selection (if we own it) and clears any data we own.
   void Clear();
 
   // It is our owner's responsibility to plumb X11 events on |xwindow_| to us.
   void OnSelectionRequest(const XSelectionRequestEvent& event);
   void OnSelectionClear(const XSelectionClearEvent& event);
   // TODO(erg): Do we also need to follow PropertyNotify events? We currently
   // don't, but there were open todos in the previous implementation.
 
  private:
   // Our X11 state.
   Display* x_display_;
   ::Window x_window_;
 
   // The X11 selection that this instance communicates on.
   ::Atom selection_name_;
 
   // The data we are currently serving.
-  scoped_ptr<SelectionFormatMap> selection_data_;
+  SelectionFormatMap format_map_;
 
   X11AtomCache atom_cache_;
 
   DISALLOW_COPY_AND_ASSIGN(SelectionOwner);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_X_SELECTION_OWNER_H_