Revert of Add empty header to fix internal project.

webrtc/system_wrappers/include/critical_section_wrapper.h

Index: webrtc/system_wrappers/include/critical_section_wrapper.h
diff --git a/webrtc/system_wrappers/include/critical_section_wrapper.h b/webrtc/system_wrappers/include/critical_section_wrapper.h
deleted file mode 100644
index 5987dcee68dfdce510b57a2419216c3e39c7a061..0000000000000000000000000000000000000000
--- a/webrtc/system_wrappers/include/critical_section_wrapper.h
+++ /dev/null
@@ -1,12 +0,0 @@
-/*
- *  Copyright 2017 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.
- */
-#ifndef WEBRTC_SYSTEM_WRAPPERS_INCLUDE_CRITICAL_SECTION_WRAPPER_H_
-#define WEBRTC_SYSTEM_WRAPPERS_INCLUDE_CRITICAL_SECTION_WRAPPER_H_
-#endif  // WEBRTC_SYSTEM_WRAPPERS_INCLUDE_CRITICAL_SECTION_WRAPPER_H_