Use a direct include of strings headers in chrome/browser/ui/a*/.

chrome/browser/ui/ash/event_rewriter_unittest.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/ui/ash/event_rewriter.h"
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/prefs/pref_member.h"
-#include "base/stringprintf.h"
+#include "base/strings/stringprintf.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/testing_pref_service_syncable.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/base/events/event.h"
 
 #if defined(OS_CHROMEOS)
 #include <X11/keysym.h>
 #include <X11/XF86keysym.h>
 #include <X11/Xlib.h>
 
@@ skipping 2269 matching lines @@
   // flag in the event is True.
   EXPECT_EQ(GetExpectedResultAsString(ui::VKEY_CONTROL,
                                       ui::EF_CONTROL_DOWN,
                                       ui::ET_KEY_PRESSED,
                                       keycode_control_l_,
                                       0U,
                                       KeyPress),
             rewritten_event);
 }
 #endif  // OS_CHROMEOS