Don't throw for unparseable frames.

lib/src/trace.dart

 // Copyright (c) 2013, 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 trace;
 
 import 'dart:collection';
 import 'dart:math' as math;
 
 import 'chain.dart';
 import 'frame.dart';
 import 'lazy_trace.dart';
+import 'unparsed_frame.dart';
 import 'utils.dart';
 import 'vm_trace.dart';
 
 final _terseRegExp = new RegExp(r"(-patch)?([/\\].*)?$");
 
 /// A RegExp to match V8's stack traces.
 ///
 /// V8's traces start with a line that's either just "Error" or else is a
 /// description of the exception that occurred. That description can be multiple
 /// lines, so we just look for any line other than the first that begins with
@@ skipping 85 matching lines @@
   }
 
   /// Parses a string representation of a stack trace.
   ///
   /// [trace] should be formatted in the same way as a Dart VM or browser stack
   /// trace.
   factory Trace.parse(String trace) {
     try {
       if (trace.isEmpty) return new Trace(<Frame>[]);
       if (trace.contains(_v8Trace)) return new Trace.parseV8(trace);
-      if (trace.startsWith("\tat ")) return new Trace.parseJSCore(trace);
+      if (trace.contains("\tat ")) return new Trace.parseJSCore(trace);
       if (trace.contains(_firefoxSafariTrace)) {
         return new Trace.parseFirefox(trace);
       }
       if (trace.contains(_friendlyTrace)) {
         return new Trace.parseFriendly(trace);
       }
 
       // Default to parsing the stack trace as a VM trace. This is also hit on
       // IE and Safari, where the stack trace is just an empty string (issue
       // 11257).
@@ skipping 126 matching lines @@
         // just get rid of them.
         // TODO(nweiz): Get rid of this logic some time after issue 22009 is
         // fixed.
         if (!frame.member.contains('<async>')) return false;
         return frame.line == null;
       };
     }
 
     var newFrames = [];
     for (var frame in frames.reversed) {
-      if (!predicate(frame)) {
+      if (frame is UnparsedFrame || !predicate(frame)) {
         newFrames.add(frame);
       } else if (newFrames.isEmpty || !predicate(newFrames.last)) {
         newFrames.add(new Frame(
             frame.uri, frame.line, frame.column, frame.member));
       }
     }
 
     if (terse) {
       newFrames = newFrames.map((frame) {
-        if (!predicate(frame)) return frame;
+        if (frame is UnparsedFrame || !predicate(frame)) return frame;
         var library = frame.library.replaceAll(_terseRegExp, '');
         return new Frame(Uri.parse(library), null, null, frame.member);
       }).toList();
       if (newFrames.length > 1 && newFrames.first.isCore) newFrames.removeAt(0);
     }
 
     return new Trace(newFrames.reversed);
   }
 
   /// Returns a human-readable string representation of [this].
   String toString() {
     // Figure out the longest path so we know how much to pad.
     var longest = frames.map((frame) => frame.location.length)
         .fold(0, math.max);
 
     // Print out the stack trace nicely formatted.
     return frames.map((frame) {
+      if (frame is UnparsedFrame) return "$frame\n";
       return '${padRight(frame.location, longest)}  ${frame.member}\n';
     }).join();
   }
 }