iwyu: Include stringprintf.h where appropriate, part 2.

chrome/browser/autofill/form_structure.cc

 // Copyright (c) 2011 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 "chrome/browser/autofill/form_structure.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/sha1.h"
+#include "base/stringprintf.h"
 #include "base/string_number_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/autofill/autofill_metrics.h"
 #include "chrome/browser/autofill/autofill_xml_parser.h"
 #include "chrome/browser/autofill/field_types.h"
 #include "chrome/browser/autofill/form_field.h"
 #include "third_party/libjingle/source/talk/xmllite/xmlelement.h"
 #include "webkit/glue/form_field.h"
 
 using webkit_glue::FormData;
@@ skipping 564 matching lines @@
     } else {
       buzz::XmlElement *field_element = new buzz::XmlElement(
           buzz::QName(kXMLElementField));
       field_element->SetAttr(buzz::QName(kAttributeSignature),
                              field->FieldSignature());
       encompassing_xml_element->AddElement(field_element);
     }
   }
   return true;
 }