[Cleanup] Remove StringPrintf from global namespace

net/proxy/proxy_resolver_v8_tracing_unittest.cc

 // Copyright (c) 2013 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 "net/proxy/proxy_resolver_v8_tracing.h"
 
 #include "base/file_util.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
 #include "base/stl_util.h"
@@ skipping 56 matching lines @@
 }
 
 class MockErrorObserver : public ProxyResolverErrorObserver {
  public:
   MockErrorObserver() : event_(true, false) {}
 
   virtual void OnPACScriptError(int line_number,
                                 const string16& error) OVERRIDE {
     {
       base::AutoLock l(lock_);
-      output += StringPrintf("Error: line %d: %s\n", line_number,
-                             UTF16ToASCII(error).c_str());
+      output += base::StringPrintf("Error: line %d: %s\n", line_number,
+                                   UTF16ToASCII(error).c_str());
     }
     event_.Signal();
   }
 
   std::string GetOutput() {
     base::AutoLock l(lock_);
     return output;
   }
 
   void WaitForOutput() {
@@ skipping 998 matching lines @@
                 proxy_uri.substr(0, proxy_uri.find(':') + 1));
     } else {
       NOTREACHED();
     }
   }
 }
 
 }  // namespace
 
 }  // namespace net