[Cleanup] Remove StringPrintf from global namespace

net/base/crl_set.cc

Index: net/base/crl_set.cc
diff --git a/net/base/crl_set.cc b/net/base/crl_set.cc
index dd73c7e1f8aa3d8c6e396fff55456142368ddf91..735bb5e96e89c32da12ce9f326fe3e223de68729 100644
--- a/net/base/crl_set.cc
+++ b/net/base/crl_set.cc
@@ -459,7 +459,7 @@ bool CRLSet::GetIsDeltaUpdate(const base::StringPiece& in_data,
 }
 
 std::string CRLSet::Serialize() const {
-  std::string header = StringPrintf(
+  std::string header = base::StringPrintf(
       "{"
       "\"Version\":0,"
       "\"ContentType\":\"CRLSet\","
@@ -481,7 +481,7 @@ std::string CRLSet::Serialize() const {
   }
   header += "]";
   if (not_after_ != 0)
-    header += StringPrintf(",\"NotAfter\":%" PRIu64, not_after_);
+    header += base::StringPrintf(",\"NotAfter\":%" PRIu64, not_after_);
   header += "}";
 
   size_t len = 2 /* header len */ + header.size();