Roll Observatory deps (charted -> ^0.3.0)

packages/csslib/lib/src/tree.dart

Index: packages/csslib/lib/src/tree.dart
diff --git a/packages/csslib/lib/src/tree.dart b/packages/csslib/lib/src/tree.dart
index 5dad435b48467053e18de2c236227ace717117fb..ba8370e96b1b1a65acb8fcca5de95fb3a2d047ac 100644
--- a/packages/csslib/lib/src/tree.dart
+++ b/packages/csslib/lib/src/tree.dart
@@ -44,6 +44,21 @@ class Negation extends TreeNode {
   String get name => 'not';
 }
 
+// calc(...)
+// TODO(terry): Hack to handle calc however the expressions should be fully
+//              parsed and in the AST.
+class CalcTerm extends LiteralTerm {
+  final LiteralTerm expr;
+
+  CalcTerm(var value, String t, this.expr, SourceSpan span)
+      : super(value, t, span);
+
+  CalcTerm clone() => new CalcTerm(value, text, expr.clone(), span);
+  visit(VisitorBase visitor) => visitor.visitCalcTerm(this);
+
+  String toString() => "$text($expr)";
+}
+
 // /*  ....   */
 class CssComment extends TreeNode {
   final String comment;
@@ -197,6 +212,7 @@ class AttributeSelector extends SimpleSelector {
       case TokenKind.NO_MATCH:
         return '';
     }
+    return null;
   }
 
   // Return the TokenKind for operator used by visitAttributeSelector.
@@ -215,6 +231,7 @@ class AttributeSelector extends SimpleSelector {
       case TokenKind.SUBSTRING_MATCH:
         return 'SUBSTRING_MATCH';
     }
+    return null;
   }
 
   String valueToString() {
@@ -572,6 +589,7 @@ class KeyFrameDirective extends Directive {
       case TokenKind.DIRECTIVE_O_KEYFRAMES:
         return '@-o-keyframes';
     }
+    return null;
   }
 
   KeyFrameDirective clone() {
@@ -676,7 +694,7 @@ class MixinDefinition extends Directive {
 
 /** Support a Sass @mixin. See http://sass-lang.com for description. */
 class MixinRulesetDirective extends MixinDefinition {
-  final List<RuleSet> rulesets;
+  final List rulesets;
 
   MixinRulesetDirective(String name, List<VarDefinitionDirective> args,
       bool varArgs, this.rulesets, SourceSpan span)