frog isolate fixes: minor changes to the isolate library + architecture.py

frog/world.dart

 // Copyright (c) 2011, 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 198 matching lines @@
       int existingPri = existing.jsnamePriority;
       int namedPri = named.jsnamePriority;
       if (existingPri > namedPri || namedPri == 0) {
         // Either existing was higher priority, or they're both 0 so first one
         // wins.
         _renameJavascriptTopName(named);
       } else if (namedPri > existingPri) {
         // New one takes priority over existing
         _renameJavascriptTopName(existing);
       } else {
-        // Two conflicting native names or names in corelib. Libraries need
-        // to be fixed.
-        world.internalError('conflicting JS name "$name" of same '
+        final msg = 'conflicting JS name "$name" of same '
             + 'priority $existingPri: (already defined in) '
-            + '${existing.span.locationText} with priority $namedPri)',
-            named.span, existing.span);
+            + '${existing.span.locationText} with priority $namedPri)';
+        if (named.isNative) {
+          // We trust that conflicting native names in builtin libraries are
+          // harmless. Most cases there are no conflicts, currently isolates
+          // in coreimpl and dart:dom define web workers to avoid adding a
+          // dependency from corelib to dart:dom.
+          world.info(msg, named.span, existing.span);
+        } else {
+          // Conflicting name in corelib needs to be fixed.
+          world.internalError(msg, named.span, existing.span);
+        }
       }
     } else {
       // No one was using the name. Take it for ourselves.
       _topNames[name] = named;
     }
   }
 
   /** Renames an [Element] that had a name conflict in the generated JS. */
   _renameJavascriptTopName(Element named) {
     named._jsname = '${named.library.jsname}_${named.jsname}';
@@ skipping 309 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;
   }
 }