Trac has some ''unusual'' or better said ''special'' conventions about default URL paths (or URL endpoints). These are specified relative to base Trac URL.

* [/chrome /chrome] - the handler for this URL just serves files that are placed in `htdocs` folder of [TracEnvironment Trac environment]. 
These files are usually images, CSS and .js that are called ''static resources'', because they won't require any server-side processing. In fact to avoid firing [TracDev/RequestHandling Trac request handling] many prefer setup when static resources are [TracCgi#MappingStaticResources served by web server] directly.