Fix for issue with incorrectly renamed private names.

frog/world.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.
 
 /** The one true [World]. */
 World world;
 
 /**
  * Experimental phase to enable await, only set when using the
  * await/awaitc.dart entrypoint.
@@ skipping 392 matching lines @@
     if (!res && options.legOnly) {
       fatal("Leg could not compile ${options.dartScript}");
       return true; // In --leg_only, always "handle" the compilation.
     }
     return res;
   }
 
   void runCompilationPhases() {
     final lib = withTiming('first pass', () => processDartScript());
     withTiming('resolve top level', resolveAll);
+    withTiming('privatization', () { makePrivateMembersUnique(lib); });
     if (experimentalAwaitPhase != null) {
       withTiming('await translation', experimentalAwaitPhase);
     }
     withTiming('analyze pass', () { analyzeCode(lib); });
     if (options.checkOnly) return;
 
     withTiming('generate code', () { generateCode(lib); });
   }
 
   String getGeneratedCode() {
@@ skipping 58 matching lines @@
 
   resolveAll() {
     for (var lib in libraries.getValues()) {
       lib.resolve();
     }
     for (var lib in libraries.getValues()) {
       lib.postResolveChecks();
     }
   }
 
+  makePrivateMembersUnique(Library rootLib) {
+    var usedNames = new Set<String>();
+    process(lib) {
+      for (var name in lib._privateMembers.getKeys()) {
+        if (usedNames.contains(name)) {
+          var members = lib._privateMembers[name];
+          String uniqueName = '_${lib.jsname}${members.jsname}';
+          members.jsname = uniqueName;
+          for (var member in members.members) {
+            member._jsname = uniqueName;
+          }
+        } else {
+          usedNames.add(name);
+        }
+      }
+    }
+
+    // Visit libraries in pre-order of imports.
+    var visited = new Set<Library>();
+    visit(lib) {
+      if (visited.contains(lib)) return;
+      visited.add(lib);
+      process(lib);
+      for (var import in lib.imports) {
+        visit(import.library);
+      }
+    }
+    visit(rootLib);
+  }
+
   findMainMethod(Library lib) {
     var main = lib.lookup('main', lib.span);
     if (main == null) {
       if (!options.checkOnly) fatal('no main method specified');
     }
     return main;
   }
 
   /**
    * Walks all code in lib and imports for analysis.
@@ skipping 127 matching lines @@
 
   withTiming(String name, f()) {
     final sw = new Stopwatch();
     sw.start();
     var result = f();
     sw.stop();
     info('$name in ${sw.elapsedInMs()}msec');
     return result;
   }
 }