Change IllegalArgumentException to ArgumentError.

pkg/logging/lib/logging.dart

Index: pkg/logging/lib/logging.dart
diff --git a/pkg/logging/lib/logging.dart b/pkg/logging/lib/logging.dart
index 3d90ad7e3fcb27036e216a1e75c503f898f6e672..6b7b13bb53f02cc018ad3603c623cbd7f72060e9 100644
--- a/pkg/logging/lib/logging.dart
+++ b/pkg/logging/lib/logging.dart
@@ -52,7 +52,7 @@ class Logger {
    */
   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];