Revert of base: Remove using:: declaration from version.h header.

chrome/installer/util/fake_installation_state.h

 // 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.
 
 #ifndef CHROME_INSTALLER_UTIL_FAKE_INSTALLATION_STATE_H_
 #define CHROME_INSTALLER_UTIL_FAKE_INSTALLATION_STATE_H_
 
 #include "base/files/file_path.h"
 #include "base/version.h"
 #include "chrome/installer/util/fake_product_state.h"
 #include "chrome/installer/util/helper.h"
 #include "chrome/installer/util/installation_state.h"
 #include "chrome/installer/util/util_constants.h"
 
 namespace installer {
 
 // An InstallationState helper for use by unit tests.
 class FakeInstallationState : public InstallationState {
  public:
   // Takes ownership of |version|.
-  void AddChrome(bool system_install,
-                 bool multi_install,
-                 base::Version* version) {
+  void AddChrome(bool system_install, bool multi_install, Version* version) {
     FakeProductState chrome_state;
     chrome_state.set_version(version);
     chrome_state.set_multi_install(multi_install);
     base::FilePath setup_exe(
         GetChromeInstallPath(system_install,
                              BrowserDistribution::GetSpecificDistribution(
                                  BrowserDistribution::CHROME_BROWSER)));
     setup_exe = setup_exe
         .AppendASCII(version->GetString())
         .Append(kInstallerDir)
@@ skipping 17 matching lines @@
 
  protected:
   ProductState* GetProducts(bool system_install) {
     return system_install ? system_products_ : user_products_;
   }
 };
 
 }  // namespace installer
 
 #endif  // CHROME_INSTALLER_UTIL_FAKE_INSTALLATION_STATE_H_