Revert of [GN] Add JSON project writer

tools/gn/json_project_writer.h

Index: tools/gn/json_project_writer.h
diff --git a/tools/gn/json_project_writer.h b/tools/gn/json_project_writer.h
deleted file mode 100644
index e69dc3ac94fdc564ee508ee3243f16d4b359b027..0000000000000000000000000000000000000000
--- a/tools/gn/json_project_writer.h
+++ /dev/null
@@ -1,26 +0,0 @@
-// Copyright (c) 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef TOOLS_GN_JSON_WRITER_H_
-#define TOOLS_GN_JSON_WRITER_H_
-
-#include "tools/gn/err.h"
-#include "tools/gn/target.h"
-
-class Builder;
-class BuildSettings;
-
-class JSONProjectWriter {
- public:
-  static bool RunAndWriteFiles(const BuildSettings* build_setting,
-                               const Builder* builder,
-                               const std::string& file_name,
-                               const std::string& exec_script,
-                               const std::string& exec_script_extra_args,
-                               const std::string& dir_filter_string,
-                               bool quiet,
-                               Err* err);
-};
-
-#endif