Remove multi-install from chrome/installer/setup.

chrome/installer/util/install_util.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.
 //
 // See the corresponding header file for description of the functions in this
 // file.
 
 #include "chrome/installer/util/install_util.h"
 
 #include <shellapi.h>
@@ skipping 478 matching lines @@
   return value == value_to_match_;
 }
 
 // static
 int InstallUtil::GetInstallReturnCode(installer::InstallStatus status) {
   switch (status) {
     case installer::FIRST_INSTALL_SUCCESS:
     case installer::INSTALL_REPAIRED:
     case installer::NEW_VERSION_UPDATED:
     case installer::IN_USE_UPDATED:
-    case installer::UNUSED_BINARIES_UNINSTALLED:
     case installer::OLD_VERSION_DOWNGRADE:
     case installer::IN_USE_DOWNGRADE:
       return 0;
     default:
       return status;
   }
 }
 
 // static
 void InstallUtil::ComposeCommandLine(const base::string16& program,
@@ skipping 124 matching lines @@
   // Open the program and see if it references the expected file.
   base::File file;
   BY_HANDLE_FILE_INFORMATION info = {};
 
   return (OpenForInfo(path, &file) &&
           GetInfo(file, &info) &&
           info.dwVolumeSerialNumber == file_info_.dwVolumeSerialNumber &&
           info.nFileIndexHigh == file_info_.nFileIndexHigh &&
           info.nFileIndexLow == file_info_.nFileIndexLow);
 }