Initial support for mixins in dartc.

compiler/java/com/google/dart/compiler/resolver/TopLevelElementBuilder.java

Index: compiler/java/com/google/dart/compiler/resolver/TopLevelElementBuilder.java
diff --git a/compiler/java/com/google/dart/compiler/resolver/TopLevelElementBuilder.java b/compiler/java/com/google/dart/compiler/resolver/TopLevelElementBuilder.java
index 89e204c072b5b16ef54f060f462f8b5749037b92..eb49f529771483ed3ab4a12ef6fb1983715c11a4 100644
--- a/compiler/java/com/google/dart/compiler/resolver/TopLevelElementBuilder.java
+++ b/compiler/java/com/google/dart/compiler/resolver/TopLevelElementBuilder.java
@@ -14,6 +14,7 @@ import com.google.dart.compiler.DartCompilerListener;
 import com.google.dart.compiler.ErrorCode;
 import com.google.dart.compiler.ast.ASTVisitor;
 import com.google.dart.compiler.ast.DartClass;
+import com.google.dart.compiler.ast.DartClassTypeAlias;
 import com.google.dart.compiler.ast.DartField;
 import com.google.dart.compiler.ast.DartFieldDefinition;
 import com.google.dart.compiler.ast.DartFunctionTypeAlias;
@@ -283,6 +284,19 @@ public class TopLevelElementBuilder {
     }
 
     @Override
+    public Void visitClassTypeAlias(DartClassTypeAlias node) {
+      ClassAliasElement element = Elements.classFromNode(node, library);
+      List<DartTypeParameter> parameterNodes = node.getTypeParameters();
+      List<TypeVariable> typeVariables = Elements.makeTypeVariables(parameterNodes, element);
+      element.setType(Types.interfaceType(
+          element,
+          Collections.<Type>unmodifiableList(typeVariables)));
+      node.setElement(element);
+      node.getName().setElement(element);
+      return null;
+    }
+    
+    @Override
     public Void visitFunctionTypeAlias(DartFunctionTypeAlias node) {
       FunctionAliasElement element = Elements.functionTypeAliasFromNode(node, library);
       List<DartTypeParameter> parameterNodes = node.getTypeParameters();