dart2js cleanup: remove unused imports and variables

pkg/compiler/lib/src/inferrer/type_graph_nodes.dart

Index: pkg/compiler/lib/src/inferrer/type_graph_nodes.dart
diff --git a/pkg/compiler/lib/src/inferrer/type_graph_nodes.dart b/pkg/compiler/lib/src/inferrer/type_graph_nodes.dart
index 181553991fa9f96d908141a9c8370e334cdf5d99..2bc367096676516be426167c5ad822175ff8150a 100644
--- a/pkg/compiler/lib/src/inferrer/type_graph_nodes.dart
+++ b/pkg/compiler/lib/src/inferrer/type_graph_nodes.dart
@@ -11,12 +11,10 @@ import '../common/names.dart' show Identifiers;
 import '../compiler.dart' show Compiler;
 import '../constants/values.dart';
 import '../cps_ir/cps_ir_nodes.dart' as cps_ir show Node;
-import '../dart_types.dart'
-    show DartType, FunctionType, InterfaceType, TypeKind;
+import '../dart_types.dart' show DartType, FunctionType, TypeKind;
 import '../elements/elements.dart';
 import '../native/native.dart' as native;
-import '../tree/tree.dart' as ast
-    show DartString, Node, LiteralBool, Send, SendSet, TryStatement;
+import '../tree/tree.dart' as ast show DartString, Node, LiteralBool, Send;
 import '../types/types.dart'
     show
         ContainerTypeMask,
@@ -27,11 +25,10 @@ import '../types/types.dart'
 import '../universe/selector.dart' show Selector;
 import '../util/util.dart' show ImmutableEmptySet, Setlet;
 import '../world.dart' show ClassWorld;
-
+import 'debug.dart' as debug;
 import 'inferrer_visitor.dart' show ArgumentsTypes;
 import 'type_graph_inferrer.dart'
     show TypeGraphInferrerEngine, TypeInformationSystem;
-import 'debug.dart' as debug;
 
 /**
  * Common class for all nodes in the graph. The current nodes are: