adapt to latest htmlunit

Author: rbri

src/main/java/org/openqa/selenium/htmlunit/HtmlUnitDriver.java

@@ -76,6 +76,7 @@
 import org.htmlunit.html.FrameWindow;
 import org.htmlunit.html.HtmlElement;
 import org.htmlunit.html.HtmlPage;
+import org.htmlunit.javascript.HtmlUnitScriptable;
 import org.htmlunit.javascript.host.Element;
 import org.htmlunit.javascript.host.Location;
 import org.htmlunit.javascript.host.html.DocumentProxy;
@@ -875,17 +876,17 @@ public Object executeAsyncScript(final String script, Object... args) {
     }
 
     private Object[] convertScriptArgs(final HtmlPage page, final Object[] args) {
-        final Object scope = page.getEnclosingWindow().getScriptableObject();
+        final HtmlUnitScriptable scope = page.getEnclosingWindow().getScriptableObject();
 
-        if (!(scope instanceof Scriptable)) {
+        if (scope == null) {
             return args;
         }
 
         final Object[] parameters = new Object[args.length];
         Context.enter();
         try {
             for (int i = 0; i < args.length; i++) {
-                parameters[i] = parseArgumentIntoJavascriptParameter((Scriptable) scope, args[i]);
+                parameters[i] = parseArgumentIntoJavascriptParameter(scope, args[i]);
             }
         }
         finally {

src/main/java/org/openqa/selenium/htmlunit/HtmlUnitWebElement.java

@@ -28,7 +28,6 @@
 
 import org.htmlunit.ScriptResult;
 import org.htmlunit.corejs.javascript.ScriptRuntime;
-import org.htmlunit.corejs.javascript.Scriptable;
 import org.htmlunit.corejs.javascript.ScriptableObject;
 import org.htmlunit.html.DisabledElement;
 import org.htmlunit.html.DomElement;
@@ -383,9 +382,9 @@ public String getAttribute(final String name) {
             return "";
         }
 
-        final Object scriptable = element_.getScriptableObject();
-        if (scriptable instanceof Scriptable) {
-            final Object slotVal = ScriptableObject.getProperty((Scriptable) scriptable, name);
+        final HtmlUnitScriptable scriptable = element_.getScriptableObject();
+        if (scriptable != null) {
+            final Object slotVal = ScriptableObject.getProperty(scriptable, name);
             if (slotVal instanceof String) {
                 return (String) slotVal;
             }