Bug 1423282 - Remove unused IPC listener Marionette:getImportedScripts. r=automatedtester

MozReview-Commit-ID: EwRaq9ljYxo

--HG--
extra : rebase_source : f018496a4593f05fc8637411492bcecb8416fd55

testing/marionette/frame.js

@@ -51,8 +51,6 @@ frame.Manager = class {
   removeMessageManagerListeners(mm) {
     mm.removeWeakMessageListener("Marionette:switchedToFrame", this.driver);
     mm.removeWeakMessageListener("Marionette:getVisibleCookies", this.driver);
-    mm.removeWeakMessageListener(
-        "Marionette:getImportedScripts", this.driver.importedScripts);
     mm.removeWeakMessageListener("Marionette:GetLogLevel", this.driver);
     mm.removeWeakMessageListener("Marionette:listenersAttached", this.driver);
     mm.removeWeakMessageListener("Marionette:register", this.driver);