Revert of Consolidate constructormagic macros with Chromium version and remove Chromium override.

webrtc/overrides/webrtc/base/constructormagic.h

Index: webrtc/overrides/webrtc/base/constructormagic.h
diff --git a/webrtc/overrides/webrtc/base/constructormagic.h b/webrtc/overrides/webrtc/base/constructormagic.h
new file mode 100644
index 0000000000000000000000000000000000000000..91e27489b1e7b3ead2424681ef23ac79735547ab
--- /dev/null
+++ b/webrtc/overrides/webrtc/base/constructormagic.h
@@ -0,0 +1,20 @@
+/*
+ *  Copyright 2009 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/constructormagic.h
+// We do this because constructor magic defines DISALLOW_COPY_AND_ASSIGN,
+// but we want to use the version from Chromium.
+
+#ifndef OVERRIDES_WEBRTC_BASE_CONSTRUCTORMAGIC_H__
+#define OVERRIDES_WEBRTC_BASE_CONSTRUCTORMAGIC_H__
+
+#include "base/macros.h"
+
+#endif  // OVERRIDES_WEBRTC_BASE_CONSTRUCTORMAGIC_H__