Allow dart2dart to output one file per library.

sdk/lib/_internal/compiler/implementation/deferred_load.dart

 // Copyright (c) 2014, 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 deferred_load;
 
 import 'dart2jslib.dart' show
     Backend,
     Compiler,
     CompilerTask,
@@ skipping 18 matching lines @@
     FunctionElement,
     LibraryElement,
     MetadataAnnotation,
     ScopeContainerElement,
     PrefixElement,
     VoidElement,
     TypedefElement,
     AstElement;
 
 import 'util/util.dart' show
-    Link;
+    Link, makeUnique;
 
 import 'util/setlet.dart' show
     Setlet;
 
 import 'tree/tree.dart' show
     LibraryTag,
     Node,
     NewExpression,
     Import,
     LibraryDependency,
@@ skipping 470 matching lines @@
       }
     }
   }
 
   /// Computes a unique string for the name field for each outputUnit.
   ///
   /// Also sets up the [hunksToLoad] mapping.
   void _assignNamesToOutputUnits(Set<OutputUnit> allOutputUnits) {
     Set<String> usedImportNames = new Set<String>();
 
-    // Returns suggestedName if it is not in usedNames. Otherwise concatenates
-    // the smallest number that makes it not appear in usedNames.
-    // Adds the result to usedNames.
-    String makeUnique(String suggestedName, Set<String> usedNames) {
-      String result = suggestedName;
-      if (usedNames.contains(suggestedName)) {
-        int counter = 0;
-        while (usedNames.contains(result)) {
-          counter++;
-          result = "$suggestedName$counter";
-        }
-      }
-      usedNames.add(result);
-      return result;
-    }
-
     // Finds the first argument to the [DeferredLibrary] annotation
     void computeImportDeferName(Import import) {
       String result;
       if (import == _fakeMainImport) {
         result = "main";
       } else if (import.isDeferred) {
         result = import.prefix.toString();
       } else {
         Link<MetadataAnnotation> metadatas = import.metadata;
         assert(metadatas != null);
@@ skipping 247 matching lines @@
     Element maybePrefix = elements[identifier];
     if (maybePrefix != null && maybePrefix.isPrefix) {
       PrefixElement prefixElement = maybePrefix;
       if (prefixElement.isDeferred) {
         return prefixElement;
       }
     }
     return null;
   }
 }