Cleanup some ambiguous and incorrect types and disable a case that in analyzer.dart that seems like…

lib/src/polyfill.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.
 
 part of csslib.parser;
 
 /**
  * CSS polyfill emits CSS to be understood by older parsers that which do not
  * understand (var, calc, etc.).
  */
@@ skipping 126 matching lines @@
       if (def.badUsage) {
         // Remove any expressions pointing to a bad var definition.
         expressions.removeAt(index);
         return;
       }
       _resolveVarUsage(currentExpressions, index,
           _findTerminalVarDefinition(_knownVarDefs, def));
     } else if (node.defaultValues.any((e) => e is VarUsage)) {
       // Don't have a VarDefinition need to use default values resolve all
       // default values.
-      var terminalDefaults = [];
+      var terminalDefaults = <Expression>[];
       for (var defaultValue in node.defaultValues) {
         terminalDefaults.addAll(resolveUsageTerminal(defaultValue));
       }
       expressions.replaceRange(index, index + 1, terminalDefaults);
     } else if (node.defaultValues.isNotEmpty){
       // No VarDefinition but default value is a terminal expression; use it.
       expressions.replaceRange(index, index + 1, node.defaultValues);
     } else {
       if (currVarDefinition != null) {
         currVarDefinition.badUsage = true;
@@ skipping 34 matching lines @@
     }
 
     // We're at a terminal just return the VarDefinition expression.
     if (result.isEmpty && varDef != null) {
       result = (varDef.expression as Expressions).expressions;
     }
 
     return result;
   }
 
-  _resolveVarUsage(List<Expressions> expressions, int index,
+  _resolveVarUsage(List<Expression> expressions, int index,
                    VarDefinition def) {
     var defExpressions = (def.expression as Expressions).expressions;
     expressions.replaceRange(index, index + 1, defExpressions);
   }
 }
 
 /** Remove all var definitions. */
 class _RemoveVarDefinitions extends Visitor {
   void visitTree(StyleSheet tree) {
     visitStyleSheet(tree);
@@ skipping 36 matching lines @@
       }
     } else {
       // Return real CSS property.
       return varDef;
     }
   }
 
   // Didn't point to a var definition that existed.
   return varDef;
 }