Use current gtk dialogs in linux_aura.

ui/base/linux_ui.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_BASE_LINUX_UI_H_
 #define UI_BASE_LINUX_UI_H_
 
+#include "ui/base/dialogs/select_file_dialog.h"
+#include "ui/base/dialogs/select_file_policy.h"

[Daniel Erat, 2012/07/27 17:21:56]

nit: just forward-declare SelectFilePolicy in the header?

 #include "ui/base/ui_export.h"
 #include "third_party/skia/include/core/SkColor.h"
 
 // The main entrypoint into Linux toolkit specific code. GTK code should only
 // be executed behind this interface.
 
 namespace gfx {
 class Image;
 }
 
@@ skipping 17 matching lines @@
   // environment.
   //
   // Can return NULL, in case no toolkit has been set. (For example, if we're
   // running with the "--ash" flag.)
   static const LinuxUI* instance();
 
   // Returns an themed image per theme_provider.h
   virtual bool UseNativeTheme() const = 0;
   virtual gfx::Image* GetThemeImageNamed(int id) const = 0;
   virtual bool GetColor(int id, SkColor* color) const = 0;
+
+  // Returns a native file selection dialog.
+  virtual SelectFileDialog* CreateSelectFileDialog(
+      SelectFileDialog::Listener* listener,
+      SelectFilePolicy* policy) const = 0;
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_LINUX_UI_H_