Use a direct include of strings headers in ui/, part 1.

ui/app_list/pagination_model_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 "ui/app_list/pagination_model.h"
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/message_loop.h"
-#include "base/stringprintf.h"
+#include "base/strings/stringprintf.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/app_list/pagination_model_observer.h"
 
 namespace app_list {
 namespace test {
 
 class TestPaginationModelObserver : public PaginationModelObserver {
  public:
   TestPaginationModelObserver()
       : model_(NULL),
@@ skipping 398 matching lines @@
   EXPECT_EQ(1, pagination_.selected_page());
 
   // But if the currently selected_page exceeds the total number of pages,
   // it automatically switches to the last page.
   pagination_.SetTotalPages(1);
   EXPECT_EQ(0, pagination_.selected_page());
 }
 
 }  // namespace test
 }  // namespace app_list