Emit to StreamCodeOutput instead of CodeBuffer.

pkg/compiler/lib/src/js_emitter/js_emitter.dart

Index: pkg/compiler/lib/src/js_emitter/js_emitter.dart
diff --git a/pkg/compiler/lib/src/js_emitter/js_emitter.dart b/pkg/compiler/lib/src/js_emitter/js_emitter.dart
index 14754c58143cb946744d8b71ec66fc0e0026292c..dfed04a73463b778f7b8404f7c2f1a6ec9f29a94 100644
--- a/pkg/compiler/lib/src/js_emitter/js_emitter.dart
+++ b/pkg/compiler/lib/src/js_emitter/js_emitter.dart
@@ -4,6 +4,8 @@
 
 library dart2js.js_emitter;
 
+import 'dart:async';
+
 import '../common.dart';
 
 import '../constants/expressions.dart';
@@ -18,8 +20,7 @@ import '../closure.dart' show
 import '../dart_types.dart' show
     TypedefType;
 
-import '../io/code_output.dart' show
-    CodeBuffer;
+import '../io/code_output.dart';
 
 import '../elements/elements.dart' show
     ConstructorBodyElement,
@@ -30,7 +31,7 @@ import '../elements/elements.dart' show
 
 import '../hash/sha1.dart' show hashOfString;
 
-// import '../helpers/helpers.dart';  // Included for debug helpers.
+import '../helpers/helpers.dart';  // Included for debug helpers.
 
 import '../js/js.dart' as jsAst;
 import '../js/js.dart' show
@@ -55,9 +56,9 @@ import 'program_builder.dart';
 
 import 'new_emitter/emitter.dart' as new_js_emitter;
 
-import '../source_file.dart' show
-    SourceFile,
-    StringSourceFile;
+import '../io/line_column_provider.dart' show
+    LineColumnCollector,
+    LineColumnProvider;
 
 import '../io/source_map_builder.dart' show
     SourceMapBuilder;