Use a direct include of strings headers in chrome/installer/, part 2.

chrome/installer/util/installation_validator.h

 // 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.
 
 #ifndef CHROME_INSTALLER_UTIL_INSTALLATION_VALIDATOR_H_
 #define CHROME_INSTALLER_UTIL_INSTALLATION_VALIDATOR_H_
 
 #include <map>
 #include <set>
 #include <utility>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "chrome/installer/util/browser_distribution.h"
 
 class CommandLine;
 
 namespace base {
 class FilePath;
 }
 
 namespace installer {
 
@@ skipping 240 matching lines @@
   // A collection of all valid installation types.
   static const InstallationType kInstallationTypes[];
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(InstallationValidator);
 };
 
 }  // namespace installer
 
 #endif  // CHROME_INSTALLER_UTIL_INSTALLATION_VALIDATOR_H_