iwyu: Include stringprintf.h where appropriate, part 1.

chrome/browser/browser_about_handler.h

 // Copyright (c) 2011 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.
 
 // Contains code for handling "about:" URLs in the browser process.
 
 #ifndef CHROME_BROWSER_BROWSER_ABOUT_HANDLER_H_
 #define CHROME_BROWSER_BROWSER_ABOUT_HANDLER_H_
 #pragma once
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/process.h"
-#include "base/string_util.h"
+#include "base/stringprintf.h"
 
 template <typename T> struct DefaultSingletonTraits;
 class GURL;
 class Profile;
 
 // Decides whether the given URL will be handled by the browser about handler
 // and returns true if so. On true, it may also modify the given URL to be the
 // final form (we fix up most "about:" URLs to be "chrome:" because WebKit
 // handles all "about:" URLs as "about:blank.
 //
@@ skipping 26 matching lines @@
 
   // Records the output for a specified header string.
   void SetOutput(const std::string& header, const std::string& output) {
     outputs_[header] = output;
   }
 
   // Callback for output returned from renderer processes.  Adds
   // the output for a canonical renderer header string that
   // incorporates the pid.
   void RendererCallback(base::ProcessId pid, const std::string& output) {
-    SetOutput(StringPrintf("Renderer PID %d", static_cast<int>(pid)), output);
+    SetOutput(
+        base::StringPrintf("Renderer PID %d", static_cast<int>(pid)), output);
   }
 
  private:
   AboutTcmallocOutputs();
   ~AboutTcmallocOutputs();
 
   AboutTcmallocOutputsType outputs_;
 
   friend struct DefaultSingletonTraits<AboutTcmallocOutputs>;
 
   DISALLOW_COPY_AND_ASSIGN(AboutTcmallocOutputs);
 };
 
 // Glue between the callback task and the method in the singleton.
 void AboutTcmallocRendererCallback(base::ProcessId pid,
                                    const std::string& output);
 #endif
 
 #endif  // CHROME_BROWSER_BROWSER_ABOUT_HANDLER_H_