GN: don't write separate files for non-binary targets

tools/gn/setup.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_SETUP_H_
 #define TOOLS_GN_SETUP_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 64 matching lines @@
   }
 
   // Read from the .gn file, these are the targets to check. If the .gn file
   // does not specify anything, this will be null. If the .gn file specifies
   // the empty list, this will be non-null but empty.
   const std::vector<LabelPattern>* check_patterns() const {
     return check_patterns_.get();
   }
 
   BuildSettings& build_settings() { return build_settings_; }
-  Builder* builder() { return builder_.get(); }
+  Builder& builder() { return builder_; }
   LoaderImpl* loader() { return loader_.get(); }
 
   // Name of the file in the root build directory that contains the build
   // arguements.
   static const char kBuildArgFileName[];
 
  private:
   // Performs the two sets of operations to run the generation before and after
   // the message loop is run.
   void RunPreMessageLoop();
@@ skipping 25 matching lines @@
   // it to just "python".
   void FillPythonPath(const base::CommandLine& cmdline);
 
   // Run config file.
   bool RunConfigFile();
 
   bool FillOtherConfig(const base::CommandLine& cmdline);
 
   BuildSettings build_settings_;
   scoped_refptr<LoaderImpl> loader_;
-  scoped_refptr<Builder> builder_;
+  Builder builder_;
 
   SourceFile root_build_file_;
 
   bool check_public_headers_;
 
   // See getter for info.
   std::unique_ptr<std::vector<LabelPattern>> check_patterns_;
 
   Scheduler scheduler_;
 
@@ skipping 16 matching lines @@
   // this around for the entire run so that Values can blame to the command
   // line when we issue errors about them.
   std::unique_ptr<InputFile> args_input_file_;
   std::vector<Token> args_tokens_;
   std::unique_ptr<ParseNode> args_root_;
 
   DISALLOW_COPY_AND_ASSIGN(Setup);
 };
 
 #endif  // TOOLS_GN_SETUP_H_