Add chain support to barback.

sdk/lib/_internal/pub/lib/src/barback/load_transformers.dart

Index: sdk/lib/_internal/pub/lib/src/barback/load_transformers.dart
diff --git a/sdk/lib/_internal/pub/lib/src/barback/load_transformers.dart b/sdk/lib/_internal/pub/lib/src/barback/load_transformers.dart
index 83a5a8c6f47fa7e4de40f192ae04a12a1a326e6a..5fdb86c1bbad67773e4f503b3e6ba39c8552d9fb 100644
--- a/sdk/lib/_internal/pub/lib/src/barback/load_transformers.dart
+++ b/sdk/lib/_internal/pub/lib/src/barback/load_transformers.dart
@@ -295,26 +295,33 @@ class CrossIsolateException implements Exception {
   /// property.
   final String message;
 
-  /// The exception's stack trace, or `null` if no stack trace was available.
-  final Trace stackTrace;
+  /// The exception's stack chain, or `null` if no stack chain was available.
+  final Chain stackTrace;
 
-  /// Loads a [CrossIsolateException] from a map.
+  /// Loads a [CrossIsolateException] from a serialized representation.
   ///
   /// [error] should be the result of [CrossIsolateException.serialize].
-  CrossIsolateException.deserialize(Map error)
-      : type = error['type'],
-        message = error['message'],
-        stackTrace = error['stack'] == null ? null :
-            new Trace.parse(error['stack']);
+  factory CrossIsolateException.deserialize(Map error) {
+    var type = error['type'];
+    var message = error['message'];
+    var stackTrace = error['stack'] == null ? null :
+            new Chain.parse(error['stack']);
+    return new CrossIsolateException._(type, message, stackTrace);
+  }
+
+  /// Loads a [CrossIsolateException] from a serialized representation.
+  ///
+  /// [error] should be the result of [CrossIsolateException.serialize].

[Bob Nystrom, 2013/12/04 17:37:21]

Update the doc comment.

[nweiz, 2013/12/04 22:41:30]

I've just gone back to not using a factory constructor; I'm not sure why I moved
away from one in the first place.

+  CrossIsolateException._(this.type, this.message, this.stackTrace);
 
-  /// Serializes [error] to a map that can safely be passed across isolate
+  /// Serializes [error] to an object that can safely be passed across isolate
   /// boundaries.
   static Map serialize(error, [StackTrace stack]) {
     if (stack == null && error is Error) stack = error.stackTrace;
     return {
       'type': error.runtimeType.toString(),
       'message': getErrorMessage(error),
-      'stack': stack == null ? null : stack.toString()
+      'stack': stack == null ? null : new Chain.forTrace(stack).toString()
     };
   }