dart2js: Fix hints in code base.

pkg/compiler/lib/src/resolution/class_hierarchy.dart

Index: pkg/compiler/lib/src/resolution/class_hierarchy.dart
diff --git a/pkg/compiler/lib/src/resolution/class_hierarchy.dart b/pkg/compiler/lib/src/resolution/class_hierarchy.dart
index f5534a89b174106b0990b204e47111646861c8ae..993b7736c43bf0b80e0dd43d3ccf95bb3fb3c38c 100644
--- a/pkg/compiler/lib/src/resolution/class_hierarchy.dart
+++ b/pkg/compiler/lib/src/resolution/class_hierarchy.dart
@@ -102,7 +102,7 @@ class ClassResolverVisitor extends TypeDefinitionVisitor {
           'cyclic resolution of class $element');
     }
 
-    InterfaceType type = element.computeType(compiler);
+    element.computeType(compiler);
     scope = new TypeDeclarationScope(scope, element);
     // TODO(ahe): It is not safe to call resolveTypeVariableBounds yet.
     // As a side-effect, this may get us back here trying to
@@ -243,7 +243,7 @@ class ClassResolverVisitor extends TypeDefinitionVisitor {
           MessageKind.DEPRECATED_TYPEDEF_MIXIN_SYNTAX);
     }
 
-    InterfaceType type = element.computeType(compiler);
+    element.computeType(compiler);
     scope = new TypeDeclarationScope(scope, element);
     resolveTypeVariableBounds(node.typeParameters);