Sync-patch with libwebp ver 0.3.1 (Id: Idea3464b)

Change-Id: Ie2de5d5be3d7ec6020810f2d80530aa9d27e82c9
diff --git a/src/utils/thread.h b/src/utils/thread.h
index 9afe096..13a61a4 100644
--- a/src/utils/thread.h
+++ b/src/utils/thread.h
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
 // -----------------------------------------------------------------------------
 //
 // Multi-threaded worker