Bug 1425047 - Enable ESLint rules no-undef and no-unused-vars for mobile/android/chrome/geckoview. r=esawin

Differential Revision: https://phabricator.services.mozilla.com/D60824

--HG--
extra : moz-landing-system : lando

mobile/android/.eslintrc.js

@@ -21,8 +21,6 @@ module.exports = {
 
   "overrides": [{
     files: [
-      // Bug 1425047.
-      "chrome/**",
       // Bug 1425048.
       "components/extensions/**",
     ],
@@ -30,6 +28,13 @@ module.exports = {
       "no-unused-vars": "off",
       "no-undef": "off",
     }
+  }, {
+    files: [
+      "chrome/geckoview/*Child.js",
+    ],
+    env: {
+      "mozilla/frame-script": true,
+    },
   }, {
     files: [
       "chrome/geckoview/**",

mobile/android/chrome/geckoview/geckoview.js

@@ -23,6 +23,10 @@ XPCOMUtils.defineLazyGetter(this, "WindowEventDispatcher", () =>
   EventDispatcher.for(window)
 );
 
+// This file assumes `warn` and `debug` are imported into scope
+// by the child scripts.
+/* global debug, warn */
+
 /**
  * ModuleManager creates and manages GeckoView modules. Each GeckoView module
  * normally consists of a JSM module file with an optional content module file.

mobile/android/chrome/geckoview/geckoview.xhtml

@@ -8,6 +8,7 @@
         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
   <script type="application/javascript" src="chrome://geckoview/content/geckoview.js"/>
   <script>
+    /* import-globals-from geckoview.js */
     window.addEventListener("DOMContentLoaded", startup, { once: true });
   </script>
 </window>