Add a couple functions to package:stack_trace.

This adds a function to convert a Trace to a VM-style StackTrace
object, and to parse a Trace-style string into a Trace.

R=jmesserly@google.com

Review URL: https://codereview.chromium.org//18029023

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/stack_trace@24611 260f80e4-7a28-3924-810f-c04153c831b5
7 files changed
tree: 62111256c409973455d4084a2dc72e734a4a93a6
  1. pkgs/