Emit to StreamCodeOutput instead of CodeBuffer.

pkg/compiler/lib/src/use_unused_api.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// This file use methods that aren't used by dart2js.dart, but that we wish to
 /// keep anyway. This might be general API that isn't currently in use,
 /// debugging aids, or API only used for testing (see TODO below).
 
 library dart2js.use_unused_api;
 
@@ skipping 174 matching lines @@
   filenames.appendSlash(null);
 }
 
 useSsa(ssa.HInstruction instruction) {
   instruction.isConstantNumber();
   new ssa.HAndOrBlockInformation(null, null, null);
   new ssa.HStatementSequenceInformation(null);
 }
 
 useCodeBuffer(io.CodeBuffer buffer) {
-  buffer.writeln();
-  new io.LineColumnCodeOutput(null);
 }
 
 usedByTests() {
   // TODO(ahe): We should try to avoid including API used only for tests. In
   // most cases, such API can be moved to a test library.
   dart2jslib.World world = null;
   dart2jslib.Compiler compiler = null;
   compiler.currentlyInUserCode();
   type_graph_inferrer.TypeGraphInferrer typeGraphInferrer = null;
   source_file_provider.SourceFileProvider sourceFileProvider = null;
@@ skipping 63 matching lines @@
   new dart_types.ResolvedTypedefType(null, null, null).unalias(null);
 }
 
 useCodeEmitterTask(js_emitter.CodeEmitterTask codeEmitterTask) {
   codeEmitterTask.oldEmitter.clearCspPrecompiledNodes();
 }
 
 useScript(dart2jslib.Script script) {
   script.copyWithFile(null);
 }