Revert of Enable GN check for webrtc/base

webrtc/system_wrappers/include/stringize_macros.h

Index: webrtc/system_wrappers/include/stringize_macros.h
diff --git a/webrtc/system_wrappers/include/stringize_macros.h b/webrtc/system_wrappers/include/stringize_macros.h
new file mode 100644
index 0000000000000000000000000000000000000000..9c8e7e9120ae2ff77447e91515c67f3e95927e34
--- /dev/null
+++ b/webrtc/system_wrappers/include/stringize_macros.h
@@ -0,0 +1,38 @@
+/*
+ *  Copyright (c) 2013 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.
+ */
+
+// Modified from the Chromium original:
+// src/base/strings/stringize_macros.h
+
+// This file defines preprocessor macros for stringizing preprocessor
+// symbols (or their output) and manipulating preprocessor symbols
+// that define strings.
+
+#ifndef WEBRTC_SYSTEM_WRAPPERS_INCLUDE_STRINGIZE_MACROS_H_
+#define WEBRTC_SYSTEM_WRAPPERS_INCLUDE_STRINGIZE_MACROS_H_
+
+// This is not very useful as it does not expand defined symbols if
+// called directly. Use its counterpart without the _NO_EXPANSION
+// suffix, below.
+#define STRINGIZE_NO_EXPANSION(x) #x
+
+// Use this to quote the provided parameter, first expanding it if it
+// is a preprocessor symbol.
+//
+// For example, if:
+//   #define A FOO
+//   #define B(x) myobj->FunctionCall(x)
+//
+// Then:
+//   STRINGIZE(A) produces "FOO"
+//   STRINGIZE(B(y)) produces "myobj->FunctionCall(y)"
+#define STRINGIZE(x) STRINGIZE_NO_EXPANSION(x)
+
+#endif  // WEBRTC_SYSTEM_WRAPPERS_INCLUDE_STRINGIZE_MACROS_H_