Cleanup references to concurrent_links in gn binary.

tools/gn/ninja_build_writer.cc

 // 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.
 
 #include "tools/gn/ninja_build_writer.h"
 
 #include <stddef.h>
 
 #include <fstream>
 #include <map>
@@ skipping 236 matching lines @@
   std::set<base::FilePath> fileset(input_files.begin(), input_files.end());
   fileset.insert(other_files.begin(), other_files.end());
 
   for (const auto& other_file : fileset)
     dep_out_ << " " << FilePathToUTF8(other_file);
 
   out_ << std::endl;
 }
 
 void NinjaBuildWriter::WriteAllPools() {
-  out_ << "pool link_pool\n"
-       << "  depth = " << default_toolchain_->concurrent_links() << std::endl
-       << std::endl;
-
   // Compute the pools referenced by all tools of all used toolchains.
   std::set<const Pool*> used_pools;
   for (const auto& pair : used_toolchains_) {
     for (int j = Toolchain::TYPE_NONE + 1; j < Toolchain::TYPE_NUMTYPES; j++) {
       Toolchain::ToolType tool_type = static_cast<Toolchain::ToolType>(j);
       const Tool* tool = pair.second->GetTool(tool_type);
       if (tool && tool->pool().ptr)
         used_pools.insert(tool->pool().ptr);
     }
   }
@@ skipping 179 matching lines @@
   EscapeOptions ninja_escape;
   ninja_escape.mode = ESCAPE_NINJA;
 
   // Escape for special chars Ninja will handle.
   std::string escaped = EscapeString(phony_name, ninja_escape, nullptr);
 
   out_ << "build " << escaped << ": phony ";
   path_output_.WriteFile(out_, target->dependency_output_file());
   out_ << std::endl;
 }