pkg/csslib: fixed analysis error, more cleanup

pkg/csslib/lib/src/css_printer.dart

Index: pkg/csslib/lib/src/css_printer.dart
diff --git a/pkg/csslib/lib/src/css_printer.dart b/pkg/csslib/lib/src/css_printer.dart
index 73c29845179cee1f919cd7feb6367db693465f91..ca3ce4dff4c903f7db4fcb9ff4cccd2046baac49 100644
--- a/pkg/csslib/lib/src/css_printer.dart
+++ b/pkg/csslib/lib/src/css_printer.dart
@@ -161,7 +161,7 @@ class CssPrinter extends Visitor {
   }
 
   void visitStyletDirective(StyletDirective node) {
-    emit('/* @stylet export as ${node._dartClassName} */\n');
+    emit('/* @stylet export as ${node.dartClassName} */\n');
   }
 
   void visitNamespaceDirective(NamespaceDirective node) {
@@ -224,7 +224,7 @@ class CssPrinter extends Visitor {
   }
 
   void visitDeclarationGroup(DeclarationGroup node) {
-    var declarations = node._declarations;
+    var declarations = node.declarations;
     var declarationsLength = declarations.length;
     for (var i = 0; i < declarationsLength; i++) {
       if (i > 0) emit(_newLine);
@@ -338,7 +338,7 @@ class CssPrinter extends Visitor {
   }
 
   void visitSelectorExpression(SelectorExpression node) {
-    var expressions = node._expressions;
+    var expressions = node.expressions;
     var expressionsLength = expressions.length;
     for (var i = 0; i < expressionsLength; i++) {
       // Add space seperator between terms without an operator.