Incorporates feedback by Nicolas for UTF-8 bytes based scanner CL

sdk/lib/_internal/compiler/implementation/apiimpl.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.
 
 library leg_apiimpl;
 
 import 'dart:async';
 
 import '../compiler.dart' as api;
 import 'dart2jslib.dart' as leg;
@@ skipping 155 matching lines @@
     void reportReadError(exception) {
       withCurrentElement(element, () {
         reportError(node,
                     leg.MessageKind.READ_SCRIPT_ERROR,
                     {'uri': readableUri, 'exception': exception});
       });
     }
 
     Uri resourceUri = translateUri(readableUri, node);
     // TODO(johnniwinther): Wrap the result from [provider] in a specialized
-    // [Future] to ensure that we never execute an asynchronous action without setting
-    // up the current element of the compiler.
-    return new Future.sync(() => callUserProvider(resourceUri))
-        .then((data) {
+    // [Future] to ensure that we never execute an asynchronous action without
+    // setting up the current element of the compiler.
+    return new Future.sync(() => callUserProvider(resourceUri)).then((data) {
       SourceFile sourceFile;
       String resourceUriString = resourceUri.toString();
       if (data is List<int>) {
         sourceFile = new Utf8BytesSourceFile(resourceUriString, data);
       } else if (data is String) {
         sourceFile = new StringSourceFile(resourceUriString, data);
       } else {
         String message = "Expected a 'String' or a 'List<int>' from the input "
                          "provider, but got: ${Error.safeToString(data)}.";
         reportReadError(message);
@@ skipping 134 matching lines @@
       rethrow;
     }
   }
 
   void diagnoseCrashInUserCode(String message, exception, stackTrace) {
     hasCrashed = true;
     print('$message: ${tryToString(exception)}');
     print(tryToString(stackTrace));
   }
 }