Use a direct include of strings headers in testing/, third_party/, tools/.

third_party/zlib/google/zip_unittest.cc

 // Copyright (c) 2011 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 <vector>
 
 #include "base/file_util.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/path_service.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
 #include "third_party/zlib/google/zip.h"
 #include "third_party/zlib/google/zip_reader.h"
 
 namespace {
 
 // Make the test a PlatformTest to setup autorelease pools properly on Mac.
 class ZipTest : public PlatformTest {
  protected:
@@ skipping 174 matching lines @@
     EXPECT_TRUE(reader.LocateAndOpenEntry(zip_file_list_[i]));
     // Check the path in the entry just in case.
     const zip::ZipReader::EntryInfo* entry_info = reader.current_entry_info();
     EXPECT_EQ(entry_info->file_path(), zip_file_list_[i]);
   }
 }
 #endif  // defined(OS_POSIX)
 
 }  // namespace