Revert 232657 "GN: toolchain threading cleanup"

trunk/src/tools/gn/toolchain.h

Index: trunk/src/tools/gn/toolchain.h
===================================================================
--- trunk/src/tools/gn/toolchain.h	(revision 232660)
+++ trunk/src/tools/gn/toolchain.h	(working copy)
@@ -70,7 +70,7 @@
     std::string rspfile_content;
   };
 
-  Toolchain(const Settings* settings, const Label& label);
+  Toolchain(const Label& label);
   virtual ~Toolchain();
 
   // Item overrides.
@@ -87,6 +87,9 @@
   const std::string& environment() const { return environment_; }
   void set_environment(const std::string& env) { environment_ = env; }
 
+  bool is_default() const { return is_default_; }
+  void set_is_default(bool id) { is_default_ = id; }
+
   // Specifies build argument overrides that will be set on the base scope. It
   // will be as if these arguments were passed in on the command line. This
   // allows a toolchain to override the OS type of the default toolchain or
@@ -97,6 +100,7 @@
  private:
   Tool tools_[TYPE_NUMTYPES];
 
+  bool is_default_;
   Scope::KeyValueMap args_;
 
   std::string environment_;