Return an empty PluginList instead of null for the

deprecated getPluginList() api.

Fix http://b/issue?id=2249732

core/java/android/webkit/WebView.java

@@ -2730,7 +2730,7 @@ public class WebView extends AbsoluteLayout
     */
     @Deprecated
     public static synchronized PluginList getPluginList() {
-        return null;
+        return new PluginList();
     }
 
    /**