[GN] Allow spaces in output names and other substitutions.

tools/gn/ninja_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_NINJA_TARGET_WRITER_H_
 #define TOOLS_GN_NINJA_TARGET_WRITER_H_
 
 #include <iosfwd>
 
 #include "base/macros.h"
 #include "tools/gn/path_output.h"
+#include "tools/gn/substitution_type.h"
 
 class FileTemplate;
 class OutputFile;
 class Settings;
 class Target;
 struct SubstitutionBits;
 
 // Generates one target's ".ninja" file. The toplevel "build.ninja" file is
 // generated by the NinjaBuildWriter.
 class NinjaTargetWriter {
@@ skipping 25 matching lines @@
   void WriteStampForTarget(const std::vector<OutputFile>& deps,
                            const std::vector<OutputFile>& order_only_deps);
 
   const Settings* settings_;  // Non-owning.
   const Target* target_;  // Non-owning.
   std::ostream& out_;
   PathOutput path_output_;
 
  private:
   void WriteCopyRules();
+  void WriteEscapedSubstitution(SubstitutionType type);
 
   DISALLOW_COPY_AND_ASSIGN(NinjaTargetWriter);
 };
 
 #endif  // TOOLS_GN_NINJA_TARGET_WRITER_H_