Change IllegalArgumentException to ArgumentError.

Review URL: https://codereview.chromium.org//10989013

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/logging@12841 260f80e4-7a28-3924-810f-c04153c831b5
diff --git a/lib/logging.dart b/lib/logging.dart
index 3d90ad7..6b7b13b 100644
--- a/lib/logging.dart
+++ b/lib/logging.dart
@@ -52,7 +52,7 @@
    */
   factory Logger(String name) {
     if (name.startsWith('.')) {
-      throw new IllegalArgumentException("name shouldn't start with a '.'");
+      throw new ArgumentError("name shouldn't start with a '.'");
     }
     if (_loggers == null) _loggers = <String, Logger>{};
     if (_loggers.containsKey(name)) return _loggers[name];