Support explicit pools in actions

tools/gn/pool.h

 // Copyright 2016 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_POOL_H_
 #define TOOLS_GN_POOL_H_
 
 #include <string>
 
 #include "tools/gn/item.h"
@@ skipping 11 matching lines @@
   Pool& operator=(const Pool&) = delete;
 
   // Item implementation.
   Pool* AsPool() override;
   const Pool* AsPool() const override;
 
   // The pool depth (number of task to run simultaneously).
   int64_t depth() const { return depth_; }
   void set_depth(int64_t depth) { depth_ = depth; }
 
+  // Console pool option
+  bool is_console() const { return console_; }
+  void set_console(bool value) { console_ = value; }
+
   // The pool name in generated ninja files.
   std::string GetNinjaName(const Label& default_toolchain) const;
 
  private:
   std::string GetNinjaName(bool include_toolchain) const;
 
   int64_t depth_ = 0;
+  bool console_ = false;
 };
 
 #endif  // TOOLS_GN_POOL_H_