run iwyu on base!

base/utf_offset_string_conversions.cc

Index: base/utf_offset_string_conversions.cc
diff --git a/base/utf_offset_string_conversions.cc b/base/utf_offset_string_conversions.cc
index 4c47ef8e8cef3c43b3289e338442889ecf312542..d8084270d3051a87ef2a7f0c28cba4541b0e8d3d 100644
--- a/base/utf_offset_string_conversions.cc
+++ b/base/utf_offset_string_conversions.cc
@@ -2,10 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/utf_offset_string_conversions.h"
+#include <stddef.h>
+#include <string>
 
+#include "base/basictypes.h"
+#include "base/string16.h"
 #include "base/string_piece.h"
 #include "base/utf_string_conversion_utils.h"
+#include "build/build_config.h"
 
 using base::PrepareForUTF16Or32Output;
 using base::ReadUnicodeCharacter;