Add SetScale to PPB_WidgetDev, use scale for painting

ppapi/api/dev/ppb_widget_dev.idl

Index: ppapi/api/dev/ppb_widget_dev.idl
diff --git a/ppapi/api/dev/ppb_widget_dev.idl b/ppapi/api/dev/ppb_widget_dev.idl
index dc97c9f5f8fcaace65e70f96d9d333a53f29f4f3..77e5de0fff9337d3b95de693b8804d1b207b84e5 100644
--- a/ppapi/api/dev/ppb_widget_dev.idl
+++ b/ppapi/api/dev/ppb_widget_dev.idl
@@ -8,7 +8,8 @@
  */
 
 label Chrome {
-  M14 = 0.3
+  M14 = 0.3,
+  M23 = 0.4
 };
 
 /**
@@ -46,4 +47,11 @@ interface PPB_Widget_Dev {
    */
   void SetLocation([in] PP_Resource widget,
                    [in] PP_Rect location);
+
+  /**
+   * Set scale used during paint operations.
+   */
+  [version=0.4]
+  void SetScale([in] PP_Resource widget,
+                [in] float_t scale);
 };