GN threading refactor

tools/gn/function_toolchain.cc

Index: tools/gn/function_toolchain.cc
diff --git a/tools/gn/function_toolchain.cc b/tools/gn/function_toolchain.cc
index dde0306fb14cdc91922c1e534c010e5c47b7400b..cbd8826fa850180a94c23a31bea212779845131a 100644
--- a/tools/gn/function_toolchain.cc
+++ b/tools/gn/function_toolchain.cc
@@ -98,14 +98,15 @@ Value RunToolchain(Scope* scope,
   const SourceDir& input_dir = scope->GetSourceDir();
   Label label(input_dir, args[0].string_value());
   if (g_scheduler->verbose_logging())
-    g_scheduler->Log("Generating toolchain", label.GetUserVisibleName(false));
+    g_scheduler->Log("Definining toolchain", label.GetUserVisibleName(false));
 
   // This object will actually be copied into the one owned by the toolchain
   // manager, but that has to be done in the lock.
-  Toolchain toolchain(scope->settings(), label);
+  scoped_ptr<Toolchain> toolchain(new Toolchain(scope->settings(), label));
+  toolchain->set_defined_from(function);
 
   Scope block_scope(scope);
-  block_scope.SetProperty(&kToolchainPropertyKey, &toolchain);
+  block_scope.SetProperty(&kToolchainPropertyKey, toolchain.get());
   block->ExecuteBlockInScope(&block_scope, err);
   block_scope.SetProperty(&kToolchainPropertyKey, NULL);
   if (err->has_error())
@@ -113,17 +114,7 @@ Value RunToolchain(Scope* scope,
   if (!block_scope.CheckForUnusedVars(err))
     return Value();
 
-  const BuildSettings* build_settings = scope->settings()->build_settings();
-  {
-    // Save the toolchain definition in the toolchain manager and mark the
-    // corresponding item in the dependency tree resolved so that targets
-    // that depend on this toolchain know it's ready.
-    base::AutoLock lock(build_settings->item_tree().lock());
-    build_settings->toolchain_manager().SetToolchainDefinitionLocked(
-        toolchain, function->GetRange(), err);
-    build_settings->item_tree().MarkItemDefinedLocked(build_settings, label,
-                                                      err);
-  }
+  scope->settings()->build_settings()->ItemDefined(toolchain.PassAs<Item>());
   return Value();
 }