dart2js: use IdGenerator for all id generation

pkg/compiler/lib/src/compiler.dart

Index: pkg/compiler/lib/src/compiler.dart
diff --git a/pkg/compiler/lib/src/compiler.dart b/pkg/compiler/lib/src/compiler.dart
index 1b01849c9558a21ac442383036edcd05909a46f6..0ec831c28f5bb9cc765b73c93e4e9387450094eb 100644
--- a/pkg/compiler/lib/src/compiler.dart
+++ b/pkg/compiler/lib/src/compiler.dart
@@ -89,7 +89,7 @@ import 'universe/world_impact.dart' show ImpactStrategy, WorldImpact;
 import 'util/util.dart' show Link, Setlet;
 import 'world.dart' show World;
 
-abstract class Compiler implements LibraryLoaderListener, IdGenerator {
+abstract class Compiler implements LibraryLoaderListener {
   final Stopwatch totalCompileTime = new Stopwatch();
   final IdGenerator idGenerator = new IdGenerator();
   World world;
@@ -391,10 +391,6 @@ abstract class Compiler implements LibraryLoaderListener, IdGenerator {
   bool get disableTypeInference =>
       options.disableTypeInference || compilationFailed;
 
-  // TODO(het): remove this and pass idGenerator directly instead
-  @deprecated
-  int getNextFreeId() => idGenerator.getNextFreeId();
-
   void unimplemented(Spannable spannable, String methodName) {
     reporter.internalError(spannable, "$methodName not implemented.");
   }