Remove (for the time being) async-await from dart2js.

pkg/compiler/lib/src/library_loader.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 dart2js.library_loader;
 
 import 'dart:async';
 
 import 'dart2jslib.dart' show
     Compiler,
@@ skipping 512 matching lines @@
           });
         });
   }
 
   /// Loads the deserialized [library] with the [handler].
   ///
   /// All libraries imported or exported transitively from [library] will be
   /// loaded as well.
   Future<LibraryElement> loadDeserializedLibrary(
       LibraryDependencyHandler handler,
       LibraryElement library) async {

[Siggi Cherem (dart-lang), 2015/07/23 00:03:06]

might be good to remove `async` as well to avoid confusion.

     compiler.onLibraryCreated(library);
     libraryCanonicalUriMap[library.canonicalUri] = library;
-    await compiler.onLibraryScanned(library, handler);
-    for (LibraryTag tag in library.tags) {
-      LibraryElement dependency = library.getLibraryFromTag(tag);
-      await createLibrary(handler, library, dependency.canonicalUri);
-    }
-    return library;
+    return compiler.onLibraryScanned(library, handler).then((_) {
+      return future.forEach(library.tags, (LibraryTag tag) {
+        LibraryElement dependency = library.getLibraryFromTag(tag);
+        return createLibrary(handler, library, dependency.canonicalUri);
+      }).then((_) => library);
+    });
   }
 
   /**
    * Create (or reuse) a library element for the library specified by the
    * [resolvedUri].
    *
    * If a new library is created, the [handler] is notified.
    */
   Future<LibraryElement> createLibrary(LibraryDependencyHandler handler,
                                        LibraryElement importingLibrary,
@@ skipping 664 matching lines @@
         }
         suffixes.add(const Link<Uri>().prepend(canonicalUri));
       }
       suffixChainMap[library] = suffixes;
       return;
     }
 
     computeSuffixes(rootLibrary, const Link<Uri>());
   }
 }