Adding an easy way to allow inline style attributes through sanitization

sdk/lib/html/dart2js/html_dart2js.dart

Index: sdk/lib/html/dart2js/html_dart2js.dart
diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index a6b0e8154f4023b46014e3567796d8b470bc4129..8836e33faea532bce9eb7f4ea05f04377b51a520 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -30821,6 +30821,21 @@ class NodeValidatorBuilder implements NodeValidator {
   }
 
   /**
+   * Allow inline styles on elements.
+   *
+   * If [tagName] is not specified then this allows inline styles on all
+   * elements. Otherwise tagName limits the styles to the specified elements.
+   */
+  void allowInlineStyles({String tagName}) {
+    if (tagName == null) {
+      tagName = '*';
+    } else {
+      tagName = tagName.toUpperCase();
+    }
+    add(new _SimpleNodeValidator(null, allowedAttributes: ['$tagName::style']));
+  }
+
+  /**
    * Allow common safe HTML5 elements and attributes.
    *
    * This list is based off of the Caja whitelists at: