run iwyu on base!

base/version.cc

Index: base/version.cc
diff --git a/base/version.cc b/base/version.cc
index 571672c801d8255b6db2285317fd932a98f992b3..25d5920a0f7404a79db21685e35f4342fc7d4b03 100644
--- a/base/version.cc
+++ b/base/version.cc
@@ -2,15 +2,16 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/version.h"
-
+#include <stddef.h>
 #include <algorithm>
+#include <string>
+#include <vector>
 
+#include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/string_number_conversions.h"
 #include "base/string_split.h"
-#include "base/string_util.h"
-#include "base/utf_string_conversions.h"
+#include "base/version.h"
 
 Version::Version() : is_valid_(false) {}