Update charted to 0.4.8 and roll

packages/stack_trace/lib/src/lazy_chain.dart

Index: packages/stack_trace/lib/src/lazy_chain.dart
diff --git a/packages/stack_trace/lib/src/lazy_chain.dart b/packages/stack_trace/lib/src/lazy_chain.dart
new file mode 100644
index 0000000000000000000000000000000000000000..55b98974a5404a1a7fdf45495a4b19ea01534486
--- /dev/null
+++ b/packages/stack_trace/lib/src/lazy_chain.dart
@@ -0,0 +1,33 @@
+// Copyright (c) 2017, 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.
+
+import 'chain.dart';
+import 'frame.dart';
+import 'lazy_trace.dart';
+import 'trace.dart';
+
+/// A thunk for lazily constructing a [Chain].
+typedef Chain ChainThunk();
+
+/// A wrapper around a [ChainThunk]. This works around issue 9579 by avoiding
+/// the conversion of native [StackTrace]s to strings until it's absolutely
+/// necessary.
+class LazyChain implements Chain {
+  final ChainThunk _thunk;
+  Chain _inner;
+
+  LazyChain(this._thunk);
+
+  Chain get _chain {
+    if (_inner == null) _inner = _thunk();
+    return _inner;
+  }
+
+  List<Trace> get traces => _chain.traces;
+  Chain get terse => _chain.terse;
+  Chain foldFrames(bool predicate(Frame frame), {bool terse: false}) =>
+      new LazyChain(() => _chain.foldFrames(predicate, terse: terse));
+  Trace toTrace() => new LazyTrace(() => _chain.toTrace());
+  String toString() => _chain.toString();
+}