invariant cleanup

pkg/compiler/lib/src/diagnostics/invariant.dart

Index: pkg/compiler/lib/src/diagnostics/invariant.dart
diff --git a/pkg/compiler/lib/src/diagnostics/invariant.dart b/pkg/compiler/lib/src/diagnostics/invariant.dart
index eb31d04b35a448af833c5de144fc06ccb9b50730..28a6b427eee2d7fcc5af3faf10fbf7684b3dd933 100644
--- a/pkg/compiler/lib/src/diagnostics/invariant.dart
+++ b/pkg/compiler/lib/src/diagnostics/invariant.dart
@@ -26,42 +26,6 @@ assertDebugMode(String message) {
       failedAt(NO_LOCATION_SPANNABLE, 'Debug mode is not enabled: $message'));
 }
 
-/**
- * Throws a [SpannableAssertionFailure] if [condition] is
- * [:false:]. [condition] must be either a [:bool:] or a no-arg
- * function returning a [:bool:].
- *
- * Use this method to provide better information for assertion by calling
- * [invariant] as the argument to an [:assert:] statement:
- *
- *     assert(invariant(position, isValid));
- *
- * [spannable] must be non-null and will be used to provide positional
- * information in the generated error message.
- */
-bool invariant(Spannable spannable, var condition, {var message: null}) {
-  // TODO(johnniwinther): Use [spannable] and [message] to provide better
-  // information on assertion errors.
-  if (spannable == null) {
-    throw new SpannableAssertionFailure(CURRENT_ELEMENT_SPANNABLE,
-        'Spannable was null for invariant. Use CURRENT_ELEMENT_SPANNABLE.');
-  }
-  if (condition is Function) {
-    condition = condition();
-    if (condition is String) {
-      message = condition;
-      condition = false;
-    }
-  }
-  if (!condition) {
-    if (message is Function) {
-      message = message();
-    }
-    throw new SpannableAssertionFailure(spannable, message);
-  }
-  return true;
-}
-
 /// Throws a [SpannableAssertionFailure].
 ///
 /// Use this method to provide better information for assertion by calling
@@ -85,5 +49,3 @@ bool failedAt(Spannable spannable, [var message]) {
   }
   throw new SpannableAssertionFailure(spannable, message);
 }
-
-typedef void InternalErrorFunction(Spannable location, String message);