Add missing copyright headers.
diff --git a/lib/src/stepper.dart b/lib/src/stepper.dart
index f878f49..cb8bb42 100644
--- a/lib/src/stepper.dart
+++ b/lib/src/stepper.dart
@@ -1,3 +1,17 @@
+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
library webdriver.stepper;
import 'dart:async';
diff --git a/lib/support/stdio_stepper.dart b/lib/support/stdio_stepper.dart
index eea1711..bb82918 100644
--- a/lib/support/stdio_stepper.dart
+++ b/lib/support/stdio_stepper.dart
@@ -1,3 +1,17 @@
+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
library webdriver.support.stdio_stepper;
import 'dart:async';
