Add arraysize to overrides to avoid macros redefinitions in Chromium

This fixes the Webrtc in Chrome FYI bots breaking.


Review URL:

Cr-Commit-Position: refs/heads/master@{#8371}
git-svn-id: 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/overrides/webrtc/base/arraysize.h b/webrtc/overrides/webrtc/base/arraysize.h
new file mode 100644
index 0000000..abc1240
--- /dev/null
+++ b/webrtc/overrides/webrtc/base/arraysize.h
@@ -0,0 +1,20 @@
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE 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.
+ */
+// This file overrides the inclusion of webrtc/base/arraysize.h
+// We do this because in Chromium it redefines arraysize, which is already
+// defined in base/macros.h.
+#include "base/macros.h"