tools/gn: Fix errors found by Facebook's flint tool.

tools/gn/commands.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/commands.h"
+
 #include "base/command_line.h"
 #include "tools/gn/builder.h"
-#include "tools/gn/commands.h"
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/item.h"
 #include "tools/gn/label.h"
 #include "tools/gn/label_pattern.h"
 #include "tools/gn/setup.h"
 #include "tools/gn/standard_out.h"
 #include "tools/gn/target.h"
 
 namespace commands {
 
@@ skipping 459 matching lines @@
   }
 }
 
 void FilterAndPrintTargetSet(bool indent,
                              const std::set<const Target*>& targets) {
   std::vector<const Target*> target_vector(targets.begin(), targets.end());
   FilterAndPrintTargets(indent, &target_vector);
 }
 
 }  // namespace commands