The source of the JavaScript.

Table 1. Attribute values
Value Description
[SomeService]?prop=tabserver.browser.src References a JavaScript contained in a service.
Note: The src attribute can reference the service that contains it, or any other service.
/demo/robot/power_on.js Specifies a URL path.
Note: If the path starts with a slash ("/"), it is resolved relative to the Developer Console web page. Otherwise, the path is resolved relative to the folder containing the service.