Update pub to new getter syntax.

utils/pub/yaml/model.dart

Index: utils/pub/yaml/model.dart
diff --git a/utils/pub/yaml/model.dart b/utils/pub/yaml/model.dart
index 0fc1b18fdd92935f62fd433d3254b54eba43e499..de9c8c83806211eaf1f5c3f8bb4ffd69712869f2 100644
--- a/utils/pub/yaml/model.dart
+++ b/utils/pub/yaml/model.dart
@@ -133,13 +133,13 @@ class _ScalarNode extends _Node {
    * Returns the string representation of the scalar. After composition, this is
    * equal to the canonical serialization of the value of the scalar.
    */
-  String get content() => _content != null ? _content : canonicalContent;
+  String get content => _content != null ? _content : canonicalContent;
 
   /**
    * Returns the canonical serialization of the value of the scalar. If the
    * value isn't given, the result of this will be "null".
    */
-  String get canonicalContent() {
+  String get canonicalContent {
     if (value == null || value is bool || value is int) return '$value';
 
     if (value is num) {