Preloads a given file into all content contexts
A marionette plugin for injecting (or replacing) apis exposed to content frames (apps, browser tabs)
"Injected" scripts will be presented and loaded before all other scripts loaded by normal content. Currently there is no way to remove a script from the marionette context after exposing it.
// expose to marionetteclient;// inject a file from the file system into all page loadsclientcontentScript;