pkg/csslib: Remove a number of unused members, prepare for release

test/var_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library var_test;
 
 import 'package:test/test.dart';
 
 import 'testing.dart';
 
@@ skipping 45 matching lines @@
 .testIt {
   color: #00f;
   background: #f00;
 }''';
 
   compileAndValidate(input, generated);
   compilePolyfillAndValidate(input, generatedPolyfill);
 }
 
 void expressionsVar() {
-  final errors = [];
   final input = ''':root {
   var-color-background: red;
   var-color-foreground: blue;
 
   var-c: #00ff00;
   var-b: var(c);
   var-a: var(b);
 
   var-image: url(test.png);
 
@@ skipping 138 matching lines @@
   unicode-range: U+0A-FF, U+980-9FF, U+????, U+3???;
 }
 .foobar {
   grid-columns: 10px ("content" 1fr 10px) [4];
 }''';
 
   compilePolyfillAndValidate(input, generatedPolyfill);
 }
 
 void defaultVar() {
-  final errors = [];
   final input = '''
 :root {
   var-color-background: red;
   var-color-foreground: blue;
 
   var-a: var(b, #0a0);
   var-b: var(c, #0b0);
   var-c: #00ff00;
 
   var-image: url(test.png);
@@ skipping 681 matching lines @@
   test('Expressions var', expressionsVar);
   test('Default value in var()', defaultVar);
   test('CSS Parser only var', parserVar);
   test('Var syntax', testVar);
   test('Indirects', testIndirects);
   test('Forward Refs', undefinedVars);
   test('Less syntax', testLess);
   test('Polyfill', polyfill);
   test('Multi-file', includes);
 }