Add the "virtual" keyword on method overrides that are missing it.

webkit/glue/plugins/pepper_widget.cc

Index: webkit/glue/plugins/pepper_widget.cc
diff --git a/webkit/glue/plugins/pepper_widget.cc b/webkit/glue/plugins/pepper_widget.cc
index e704e8cc1f0c247e230f179745659bdcf15a0f94..9fc762bed2ab9841451b36e308bac9c511be97b5 100644
--- a/webkit/glue/plugins/pepper_widget.cc
+++ b/webkit/glue/plugins/pepper_widget.cc
@@ -73,6 +73,10 @@ const PPB_Widget_Dev* Widget::GetInterface() {
   return &ppb_widget;
 }
 
+Widget* Widget::AsWidget() {
+  return this;
+}
+
 bool Widget::GetLocation(PP_Rect* location) {
   *location = location_;
   return true;