Revert "Add optional message to assert in Dart2js - continued"

sdk/lib/_internal/js_runtime/lib/js_helper.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 _js_helper;
 
 import 'dart:_js_embedded_names' show
     DEFERRED_LIBRARY_URIS,
     DEFERRED_LIBRARY_HASHES,
     GET_TYPE_FROM_NAME,
@@ skipping 3303 matching lines @@
   String toString() => message;
 }
 
 class FallThroughErrorImplementation extends FallThroughError {
   FallThroughErrorImplementation();
   String toString() => "Switch case fall-through.";
 }
 
 /**
  * Helper function for implementing asserts. The compiler treats this specially.
- *
- * Returns the negation of the condition. That is: `true` if the assert should
- * fail.
  */
-bool assertTest(condition) {
-  // Do bool success check first, it is common and faster than 'is Function'.
-  if (true == condition) return false;
-  if (condition is Function) condition = condition();
-  if (condition is bool) return !condition;
-  throw new TypeErrorImplementation(condition, 'bool');
+void assertHelper(condition) {
+  // Do a bool check first because it is common and faster than 'is Function'.
+  if (condition is !bool) {
+    if (condition is Function) condition = condition();
+    if (condition is !bool) {
+      throw new TypeErrorImplementation(condition, 'bool');
+    }
+  }
+  // Compare to true to avoid boolean conversion check in checked
+  // mode.
+  if (true != condition) throw new AssertionError();
 }
 
 /**
- * Helper function for implementing asserts with messages.
- * The compiler treats this specially.
- */
-void assertThrow(Object message) {
-  throw new _AssertionError(message);
-}
-
-/**
- * Helper function for implementing asserts without messages.
- * The compiler treats this specially.
- */
-@NoInline()
-void assertHelper(condition) {
-  if (assertTest(condition)) throw new AssertionError();
-}
-
-/**
  * Called by generated code when a method that must be statically
  * resolved cannot be found.
  */
 void throwNoSuchMethod(obj, name, arguments, expectedArgumentNames) {
   Symbol memberName = new _symbol_dev.Symbol.unvalidated(name);
   throw new NoSuchMethodError(obj, memberName, arguments,
                               new Map<Symbol, dynamic>(),
                               expectedArgumentNames);
 }
 
@@ skipping 639 matching lines @@
   throw new MainError("No top-level function named 'main'.");
 }
 
 void badMain() {
   throw new MainError("'main' is not a function.");
 }
 
 void mainHasTooManyParameters() {
   throw new MainError("'main' expects too many parameters.");
 }
-
-class _AssertionError extends AssertionError {
-  final _message;
-  _AssertionError(this._message);
-
-  String toString() => "Assertion failed: " + Error.safeToString(_message);
-}