Bug 1434399 part 12. Remove JS uses of nsIDOMXULDocument. r=mystor

MozReview-Commit-ID: HUK8ahBwG0e

devtools/server/actors/webextension.js

@@ -12,6 +12,7 @@ const makeDebugger = require("./utils/make-debugger");
 
 loader.lazyRequireGetter(this, "mapURIToAddonID", "devtools/server/actors/utils/map-uri-to-addon-id");
 loader.lazyRequireGetter(this, "unwrapDebuggerObjectGlobal", "devtools/server/actors/script", true);
+loader.lazyRequireGetter(this, "ChromeUtils");
 
 const FALLBACK_DOC_MESSAGE = "Your addon does not have any document opened yet.";
 
@@ -347,7 +348,7 @@ WebExtensionChildActor.prototype._shouldAddNewGlobalAsDebuggee = function (newGl
     }
 
     // Filter out any global which contains a XUL document.
-    if (global.document instanceof Ci.nsIDOMXULDocument) {
+    if (ChromeUtils.getClassName(global.document) == "XULDocument") {
       return false;
     }
 

toolkit/content/widgets/textbox.xml

@@ -519,7 +519,7 @@
             this._spellCheckInitialized = true;
 
             const CI = Components.interfaces;
-            if (!(document instanceof CI.nsIDOMXULDocument))
+            if (ChromeUtils.getClassName(document) != "XULDocument")
               return null;
 
             var textbox = document.getBindingParent(this);