Fix hints reported by analyzer.

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

Index: pkg/compiler/lib/src/resolution/resolution.dart
diff --git a/pkg/compiler/lib/src/resolution/resolution.dart b/pkg/compiler/lib/src/resolution/resolution.dart
index 3210976f26fdeb20a402e163f5725683ea2d797a..2f63b8103bdaef0de069c4100230253ef72a52ea 100644
--- a/pkg/compiler/lib/src/resolution/resolution.dart
+++ b/pkg/compiler/lib/src/resolution/resolution.dart
@@ -47,7 +47,7 @@ import '../tokens/token.dart'
 import '../tree/tree.dart';
 import '../universe/call_structure.dart' show CallStructure;
 import '../universe/feature.dart' show Feature;
-import '../universe/use.dart' show StaticUse, TypeUse;
+import '../universe/use.dart' show StaticUse;
 import '../universe/world_impact.dart' show WorldImpact;
 import '../util/util.dart' show Link, Setlet;
 import '../world.dart';
@@ -516,7 +516,6 @@ class ResolverTask extends CompilerTask {
       ResolvedAst resolvedAst = factory.resolvedAst;
       assert(invariant(node, resolvedAst != null,
           message: 'No ResolvedAst for $factory.'));
-      FunctionExpression functionNode = resolvedAst.node;
       RedirectingFactoryBody redirectionNode = resolvedAst.body;
       ResolutionDartType factoryType =
           resolvedAst.elements.getType(redirectionNode);