Initial support for mixins in dartc.

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

Index: compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java
diff --git a/compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java b/compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java
index b29e6bda5b7d7ae6f0f306b47aeb3d91d18fed75..03e72ff4847ce267bb4e7566504680d5ff39dd9a 100644
--- a/compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java
+++ b/compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java
@@ -12,6 +12,7 @@ import com.google.dart.compiler.PackageLibraryManager;
 import com.google.dart.compiler.Source;
 import com.google.dart.compiler.SubSystem;
 import com.google.dart.compiler.ast.ASTVisitor;
+import com.google.dart.compiler.ast.DartClassTypeAlias;
 import com.google.dart.compiler.ast.DartFunctionExpression;
 import com.google.dart.compiler.ast.DartFunctionTypeAlias;
 import com.google.dart.compiler.ast.DartIdentifier;
@@ -339,6 +340,10 @@ public class ResolutionContext implements ResolutionErrorListener {
   void pushFunctionAliasScope(DartFunctionTypeAlias x) {
     pushScope(x.getName().getName() == null ? "<function>" : x.getName().getName());
   }
+  
+  void pushClassAliasScope(DartClassTypeAlias x) {
+    pushScope(x.getName().getName() == null ? "<classTypeAlias>" : x.getName().getName());
+  }
 
   AssertionError internalError(HasSourceInfo node, String message, Object... arguments) {
     message = String.format(message, arguments);