[Cleanup] Remove StringPrintf from global namespace

net/disk_cache/simple/simple_synchronous_entry.cc

Index: net/disk_cache/simple/simple_synchronous_entry.cc
diff --git a/net/disk_cache/simple/simple_synchronous_entry.cc b/net/disk_cache/simple/simple_synchronous_entry.cc
index 8dfa3634adb41ac2e8b8d949cb3463ec75c10de7..9f5c91b4f8a0fa0239ed6e89fa0b15946c2453cb 100644
--- a/net/disk_cache/simple/simple_synchronous_entry.cc
+++ b/net/disk_cache/simple/simple_synchronous_entry.cc
@@ -41,12 +41,12 @@ namespace {
 
 std::string GetFilenameForKeyAndIndex(const std::string& key, int index) {
   const std::string sha_hash = base::SHA1HashString(key);
-  return StringPrintf("%02x%02x%02x%02x%02x_%1d",
-                      implicit_cast<unsigned char>(sha_hash[0]),
-                      implicit_cast<unsigned char>(sha_hash[1]),
-                      implicit_cast<unsigned char>(sha_hash[2]),
-                      implicit_cast<unsigned char>(sha_hash[3]),
-                      implicit_cast<unsigned char>(sha_hash[4]), index);
+  return base::StringPrintf("%02x%02x%02x%02x%02x_%1d",
+                            implicit_cast<unsigned char>(sha_hash[0]),
+                            implicit_cast<unsigned char>(sha_hash[1]),
+                            implicit_cast<unsigned char>(sha_hash[2]),
+                            implicit_cast<unsigned char>(sha_hash[3]),
+                            implicit_cast<unsigned char>(sha_hash[4]), index);
 }
 
 int32 DataSizeFromKeyAndFileSize(size_t key_size, int64 file_size) {