Remove methods on StackTrace class.

The API is not ready for finalization, so we remove it for further
development after M4.

Makes dart2js's StackTrace object implement dart:core's StackTrace.
Marks dart2js stack-trace tests as Fail instead of Skip.

Review URL: https://codereview.chromium.org//14009004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/stack_trace@21437 260f80e4-7a28-3924-810f-c04153c831b5

pkgs/stack_trace/lib/src/trace.dart

diff --git a/pkgs/stack_trace/lib/src/trace.dart b/pkgs/stack_trace/lib/src/trace.dart
index 33b2dd4..fa0c313 100644
--- a/pkgs/stack_trace/lib/src/trace.dart
+++ b/pkgs/stack_trace/lib/src/trace.dart
@@ -52,7 +52,7 @@
   /// a [Trace], it will be returned as-is.
   factory Trace.from(StackTrace trace) {
     if (trace is Trace) return trace;
-    return new Trace.parse(trace.fullStackTrace);
+    return new Trace.parse(trace.toString());
   }
 
   /// Parses a string representation of a stack trace.