Remove GN GYP generator.

tools/gn/gyp_action_target_writer.h

-// Copyright (c) 2013 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_GYP_ACTION_TARGET_WRITER_H_
-#define TOOLS_GN_GYP_ACTION_TARGET_WRITER_H_
-
-#include "base/compiler_specific.h"
-#include "tools/gn/gyp_target_writer.h"
-#include "tools/gn/target.h"
-#include "tools/gn/toolchain.h"
-
-class GypActionTargetWriter : public GypTargetWriter {
- public:
-  GypActionTargetWriter(const TargetGroup& group,
-                        const Toolchain* toolchain,
-                        const SourceDir& gyp_dir,
-                        std::ostream& out);
-  virtual ~GypActionTargetWriter();
-
-  virtual void Run() OVERRIDE;
-
- private:
-  void WriteActionInputs(int indent);
-  void WriteActionOutputs(int indent);
-
-  DISALLOW_COPY_AND_ASSIGN(GypActionTargetWriter);
-};
-
-#endif  // TOOLS_GN_GYP_ACTION_TARGET_WRITER_H_