GN: toolchain threading cleanup

tools/gn/toolchain.h

Index: tools/gn/toolchain.h
diff --git a/tools/gn/toolchain.h b/tools/gn/toolchain.h
index 106f2f4bc73943ed8214b44b34cae40330229da5..210c2c088c6027b71b5bd827afd3ef30c7378f8a 100644
--- a/tools/gn/toolchain.h
+++ b/tools/gn/toolchain.h
@@ -70,7 +70,7 @@ class Toolchain : public Item {
     std::string rspfile_content;
   };
 
-  Toolchain(const Label& label);
+  Toolchain(const Settings* settings, const Label& label);
   virtual ~Toolchain();
 
   // Item overrides.
@@ -87,9 +87,6 @@ class Toolchain : public Item {
   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
@@ -100,7 +97,6 @@ class Toolchain : public Item {
  private:
   Tool tools_[TYPE_NUMTYPES];
 
-  bool is_default_;
   Scope::KeyValueMap args_;
 
   std::string environment_;