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

content/browser/accessibility/dump_accessibility_tree_browsertest.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 <set>
 #include <string>
 #include <vector>
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/path_service.h"
-#include "base/string_util.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/browser/accessibility/accessibility_tree_formatter.h"
 #include "content/browser/accessibility/browser_accessibility.h"
 #include "content/browser/accessibility/browser_accessibility_manager.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/port/browser/render_widget_host_view_port.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/content_paths.h"
 #include "content/public/test/test_utils.h"
 #include "content/shell/shell.h"
@@ skipping 426 matching lines @@
 
 IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest, AccessibilityUl) {
   RunTest(FILE_PATH_LITERAL("ul.html"));
 }
 
 IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest, AccessibilityWbr) {
   RunTest(FILE_PATH_LITERAL("wbr.html"));
 }
 
 }  // namespace content