Add stackTrace to Error object.

sdk/lib/_internal/lib/js_helper.dart

 // Copyright (c) 2012, 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 _js_helper;
 
 import 'dart:collection';
 import 'dart:_foreign_helper' show DART_CLOSURE_TO_JS,
                                    JS,
                                    JS_CALL_IN_ISOLATE,
@@ skipping 661 matching lines @@
   return value;
 }
 
 /**
  * Wrap the given Dart object and record a stack trace.
  *
  * The code in [unwrapException] deals with getting the original Dart
  * object out of the wrapper again.
  */
 wrapException(ex) {
-  if (ex == null) ex = const NullThrownError();
+  if (ex == null) ex = new NullThrownError();
   var wrapper = new DartError(ex);
 
   if (JS('bool', '!!Error.captureStackTrace')) {
     // Use V8 API for recording a "fast" stack trace (this installs a
     // "stack" property getter on [wrapper]).
     JS('void', r'Error.captureStackTrace(#, #)',
        wrapper, RAW_DART_FUNCTION_REF(wrapException));
   } else {
     // Otherwise, produce a stack trace and record it in the wrapper.
     // This is a slower way to create a stack trace which works on
@@ skipping 323 matching lines @@
 }
 
 jsPropertyAccess(var jsObject, String property) {
   return JS('var', r'#[#]', jsObject, property);
 }
 
 /**
  * Called at the end of unaborted switch cases to get the singleton
  * FallThroughError exception that will be thrown.
  */
-getFallThroughError() => const FallThroughErrorImplementation();
+getFallThroughError() => new FallThroughErrorImplementation();
 
 /**
  * Represents the type dynamic. The compiler treats this specially.
  */
 abstract class Dynamic_ {
 }
 
 /**
  * A metadata annotation describing the types instantiated by a native element.
  *
@@ skipping 395 matching lines @@
   CastErrorImplementation.malformedTypeCast(Object value,
                                             String type, String reasons)
       : message = "CastError: Type '${Primitives.objectTypeName(value)}' "
                   "cannot be cast to type '$type' because '$type' is "
                   "malformed: $reasons.";
 
 
   String toString() => message;
 }
 
-class FallThroughErrorImplementation implements FallThroughError {
-  const FallThroughErrorImplementation();
+class FallThroughErrorImplementation extends FallThroughError {
+  FallThroughErrorImplementation();
   String toString() => "Switch case fall-through.";
 }
 
 /**
  * Helper function for implementing asserts. The compiler treats this specially.
  */
 void assertHelper(condition) {
   if (condition is Function) condition = condition();
   if (condition is !bool) {
     throw new TypeErrorImplementation(condition, 'bool');
@@ skipping 17 matching lines @@
  * field that is currently being initialized.
  */
 void throwCyclicInit(String staticName) {
   throw new CyclicInitializationError(
       "Cyclic initialization for static $staticName");
 }
 
 /**
  * Error thrown when a runtime error occurs.
  */
-class RuntimeError implements Error {
+class RuntimeError extends Error {
   final message;
   RuntimeError(this.message);
   String toString() => "RuntimeError: $message";
 }