GN: Use build directory for CD for scripts

tools/gn/ninja_script_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_SCRIPT_TARGET_WRITER_H_
 #define TOOLS_GN_NINJA_SCRIPT_TARGET_WRITER_H_
 
 #include "base/compiler_specific.h"
 #include "tools/gn/ninja_target_writer.h"
 
 // Writes a .ninja file for a custom script target type.
 class NinjaScriptTargetWriter : public NinjaTargetWriter {
  public:
   NinjaScriptTargetWriter(const Target* target, std::ostream& out);
   virtual ~NinjaScriptTargetWriter();
 
   virtual void Run() OVERRIDE;
 
  private:
   bool has_sources() const { return !target_->sources().empty(); }
 
   // Writes the Ninja rule for invoking the script.
   //
   // Returns the name of the custom rule generated. This will be based on the
   // target name, and will include the string "$unique_name" if there are
   // multiple inputs.
-  std::string WriteRuleDefinition(const std::string& script_relative_to_cd);
+  std::string WriteRuleDefinition();
 
   // Writes the rules for compiling each source, writing all output files
   // to the given vector.
   //
   // implicit_deps is a precomputed string of all ninja files that are common
   // to each build step, it starts with a "|" if it's nonempty.
   void WriteSourceRules(const std::string& custom_rule_name,
                         const std::string& implicit_deps,
-                        const SourceDir& script_cd,
-                        const std::string& script_cd_to_root,
                         std::vector<OutputFile>* output_files);
 
   void WriteArg(const std::string& arg);
 
   // Writes the .stamp rule that names this target and collects all invocations
   // of the script into one thing that other targets can depend on.
   void WriteStamp(const std::vector<OutputFile>& output_files);
 
   DISALLOW_COPY_AND_ASSIGN(NinjaScriptTargetWriter);
 };
 
 #endif  // TOOLS_GN_NINJA_SCRIPT_TARGET_WRITER_H_