base: Remove 'using' declaration of StringPrintV.

chrome/common/libxml_utils.cc

Index: chrome/common/libxml_utils.cc
diff --git a/chrome/common/libxml_utils.cc b/chrome/common/libxml_utils.cc
index f06df72fb249110fbd6e58d65893b47a57eda0fc..009f0d3c1f965337b5fd7449ca6ba03b8127faa4 100644
--- a/chrome/common/libxml_utils.cc
+++ b/chrome/common/libxml_utils.cc
@@ -6,7 +6,7 @@
 
 #include "base/compiler_specific.h"
 #include "base/logging.h"
-#include "base/string_util.h"
+#include "base/stringprintf.h"
 
 #include "libxml/xmlreader.h"
 
@@ -35,7 +35,7 @@ void XmlReader::GenericErrorCallback(void* context, const char* msg, ...) {
   va_start(args, msg);
 
   XmlReader* reader = static_cast<XmlReader*>(context);
-  reader->errors_.append(StringPrintV(msg, args));
+  reader->errors_.append(base::StringPrintV(msg, args));
   va_end(args);
 }