places-menu: can now ask user for info on mounting

When we try to launch an application for an uri where the enclosing
mount is not yet mounted we might need information from the user
such as passwwords. Using a MountOperation makes this possible.

https://bugzilla.gnome.org/show_bug.cgi?id=781788

extensions/places-menu/placeDisplay.js

@@ -12,6 +12,7 @@ const DND = imports.ui.dnd;
 const Main = imports.ui.main;
 const Params = imports.misc.params;
 const Search = imports.ui.search;
+const ShellMountOperation = imports.ui.shellMountOperation;
 const Util = imports.misc.util;
 
 const Gettext = imports.gettext.domain('gnome-shell-extensions');
@@ -49,9 +50,17 @@ const PlaceInfo = new Lang.Class({
             try {
                 Gio.AppInfo.launch_default_for_uri_finish(result);
             } catch(e if e.matches(Gio.IOErrorEnum, Gio.IOErrorEnum.NOT_MOUNTED)) {
-                this.file.mount_enclosing_volume(0, null, null, (file, result) => {
+                let source = {
+                    get_icon: () => { return this.icon; }
+                };
+                let op = new ShellMountOperation.ShellMountOperation(source);
+                this.file.mount_enclosing_volume(0, op.mountOp, null, (file, result) => {
                     try {
+                        op.close();
                         file.mount_enclosing_volume_finish(result);
+                    } catch(e if e.matches(Gio.IOErrorEnum, Gio.IOErrorEnum.FAILED_HANDLED)) {
+                        // e.g. user canceled the password dialog
+                        return;
                     } catch(e) {
                         Main.notifyError(_("Failed to mount volume for “%s”").format(this.name), e.message);
                         return;