Include sstream instead of iostream to avoid the additional IO static initializer

chrome/browser/extensions/api/system_info_cpu/cpu_info_provider_linux.cc

 // Copyright (c) 2012 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 "chrome/browser/extensions/api/system_info_cpu/cpu_info_provider.h"
 
 #include <cstdio>
-#include <iostream>
+#include <sstream>
 
 #include "base/file_util.h"
 #include "base/format_macros.h"
 
 namespace extensions {
 
 namespace {
 
 const char kProcStat[] = "/proc/stat";
 
@@ skipping 25 matching lines @@
     time.kernel = sys;
     time.user = user + nice;
     time.idle = idle;
     results.push_back(time);
   }
   times->swap(results);
   return true;
 }
 
 }  // namespace extensions