GN: toolchain threading cleanup

tools/gn/scope_per_file_provider.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/scope_per_file_provider.h"
 
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/settings.h"
 #include "tools/gn/source_file.h"
 #include "tools/gn/toolchain_manager.h"
@@ skipping 25 matching lines @@
   if (ident == variables::kTargetGenDir)
     return GetTargetGenDir();
   if (ident == variables::kTargetOutDir)
     return GetTargetOutDir();
   return NULL;
 }
 
 const Value* ScopePerFileProvider::GetCurrentToolchain() {
   if (!current_toolchain_) {
     current_toolchain_.reset(new Value(NULL,
-        scope_->settings()->toolchain()->label().GetUserVisibleName(false)));
+        scope_->settings()->toolchain_label().GetUserVisibleName(false)));
   }
   return current_toolchain_.get();
 }
 
 const Value* ScopePerFileProvider::GetDefaultToolchain() {
   if (!default_toolchain_) {
     const ToolchainManager& toolchain_manager =
         scope_->settings()->build_settings()->toolchain_manager();
     default_toolchain_.reset(new Value(NULL,
         toolchain_manager.GetDefaultToolchainUnlocked().GetUserVisibleName(
@@ skipping 98 matching lines @@
   const std::string& dir_value = scope_->GetSourceDir().value();
 
   if (dir_value == "//")
     return "//.";
 
   // Trim off a leading and trailing slash. So "//foo/bar/" -> /foo/bar".
   DCHECK(dir_value.size() > 2 && dir_value[0] == '/' &&
          dir_value[dir_value.size() - 1] == '/');
   return dir_value.substr(1, dir_value.size() - 2);
 }