Make File-Picker modal on Linux

ui/shell_dialogs/select_file_dialog.cc

 // 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 "ui/shell_dialogs/select_file_dialog.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "build/build_config.h"
@@ skipping 110 matching lines @@
         FROM_HERE,
         base::Bind(&SelectFileDialog::CancelFileSelection, this, params));
     return;
   }
 
   // Call the platform specific implementation of the file selection dialog.
   SelectFileImpl(type, title, default_path, file_types, file_type_index,
                  default_extension, owning_window, params);
 }
 
+void SelectFileDialog::Close() {
+   CloseImpl();
+}
+
 bool SelectFileDialog::HasMultipleFileTypeChoices() {
   return HasMultipleFileTypeChoicesImpl();
 }
 
 // static
 void SelectFileDialog::SetShellDialogsDelegate(ShellDialogsDelegate* delegate) {
   g_shell_dialogs_delegate_ = delegate;
 }
 
 SelectFileDialog::SelectFileDialog(Listener* listener,
                                    ui::SelectFilePolicy* policy)
     : listener_(listener),
       select_file_policy_(policy) {
   DCHECK(listener_);
 }
 
 SelectFileDialog::~SelectFileDialog() {}
 
 void SelectFileDialog::CancelFileSelection(void* params) {
   if (listener_)
     listener_->FileSelectionCanceled(params);
 }
 
 ShellDialogsDelegate* SelectFileDialog::GetShellDialogsDelegate() {
   return g_shell_dialogs_delegate_;
 }
 
 }  // namespace ui