function userCallback(newMedia)
        {
            if (newMedia) {
                this._parentPane._styleSheetMediaEdited(media, newMedia);
                this._parentPane._refreshUpdate(this);
            }
            delete this._parentPane._userOperation;
            this._editingMediaTextCommittedForTest();
        }
@param {?WebInspector.CSSMedia} newMedia
@this {WebInspector.StylePropertiesSection}