Use a direct include of strings headers in chrome/browser/extensions/, part 3.

BUG=247723
TEST=none
[email protected]

Review URL: https://chromiumcodereview.appspot.com/16402006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@205295 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/extensions/extension_service.cc b/chrome/browser/extensions/extension_service.cc
index 1d03d3a..1f7bde7 100644
--- a/chrome/browser/extensions/extension_service.cc
+++ b/chrome/browser/extensions/extension_service.cc
@@ -17,9 +17,9 @@
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
 #include "base/stl_util.h"
-#include "base/string_util.h"
-#include "base/stringprintf.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/threading/thread_restrictions.h"