base: Get rid of 'using' declaration of StringAppendF.

net/tools/flip_server/balsa_headers.cc

Index: net/tools/flip_server/balsa_headers.cc
diff --git a/net/tools/flip_server/balsa_headers.cc b/net/tools/flip_server/balsa_headers.cc
index dfdbb6135c47e1fda6cea139cecebecd461cfdd5..2196cd448f2ff1a637424d9837aacd0ccf893d65 100644
--- a/net/tools/flip_server/balsa_headers.cc
+++ b/net/tools/flip_server/balsa_headers.cc
@@ -555,22 +555,23 @@ void BalsaHeaders::DumpToString(std::string* str) const {
   // Then check whether the header is in a partially parsed state. If so, just
   // dump the raw data.
   if (balsa_buffer_.can_write_to_contiguous_buffer()) {
-    StringAppendF(str, "\n<incomplete header len: %d>\n%.*s\n",
-                  buffer_length, buffer_length, OriginalHeaderStreamBegin());
+    base::StringAppendF(str, "\n<incomplete header len: %d>\n%.*s\n",
+                        buffer_length, buffer_length,
+                        OriginalHeaderStreamBegin());
     return;
   }
 
   // If the header is complete, then just dump them with the logical key value
   // pair.
   str->reserve(str->size() + GetSizeForWriteBuffer());
-  StringAppendF(str, "\n %.*s\n",
-                static_cast<int>(firstline.size()),
-                firstline.data());
+  base::StringAppendF(str, "\n %.*s\n",
+                      static_cast<int>(firstline.size()),
+                      firstline.data());
   BalsaHeaders::const_header_lines_iterator i = header_lines_begin();
   for (; i != header_lines_end(); ++i) {
-    StringAppendF(str, " %.*s: %.*s\n",
-                  static_cast<int>(i->first.size()), i->first.data(),
-                  static_cast<int>(i->second.size()), i->second.data());
+    base::StringAppendF(str, " %.*s: %.*s\n",
+                        static_cast<int>(i->first.size()), i->first.data(),
+                        static_cast<int>(i->second.size()), i->second.data());
   }
 }