Hook up GN official build and branding.

tools/gn/loader.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/loader.h"
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "base/stl_util.h"
 #include "tools/gn/build_settings.h"
@@ skipping 275 matching lines @@
   ScopedTrace trace(TraceItem::TRACE_FILE_EXECUTE,
       settings->build_settings()->build_config_file().value());
   trace.SetToolchain(settings->toolchain_label());
 
   const BlockNode* root_block = root->AsBlock();
   Err err;
   root_block->ExecuteBlockInScope(base_config, &err);
 
   trace.Done();
 
+  if (err.has_error())
+    g_scheduler->FailWithError(err);
+
   base_config->ClearProcessingBuildConfig();
   if (settings->is_default()) {
     // The default toolchain must have been set in the default build config
     // file.
     if (default_toolchain_label.is_null()) {
       g_scheduler->FailWithError(Err(Location(),
           "The default build config file did not call set_default_toolchain()",
           "If you don't call this, I can't figure out what toolchain to use\n"
           "for all of this code."));
     } else {
@@ skipping 83 matching lines @@
     const SourceFile& file_name,
     const base::Callback<void(const ParseNode*)>& callback,
     Err* err) {
   if (async_load_file_.is_null()) {
     return g_scheduler->input_file_manager()->AsyncLoadFile(
         origin, build_settings, file_name, callback, err);
   }
   return async_load_file_.Run(
       origin, build_settings, file_name, callback, err);
 }