Fix missing variable MSVS expansion of copies arguments with Ninja.

test/ninja/normalize-paths-win/gyptest-normalize-paths.py

 #!/usr/bin/env python
 
 # Copyright (c) 2012 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """
 Make sure paths are normalized with VS macros properly expanded on Windows.
 """
 
@@ skipping 13 matching lines @@
   if '$!product_dir' in subninja:
     test.fail_test()
   if 'out\\Default' in subninja:
     test.fail_test()
 
   second = open(test.built_file_path('obj/second.ninja')).read()
   if ('..\\..\\things\\AnotherName.exe' in second or
       'AnotherName.exe' not in second):
     test.fail_test()
 
+  copytarget = open(test.built_file_path('obj/copy_target.ninja')).read()
+  print copytarget
+  if '$(VSInstallDir)' in copytarget:
+    test.fail_test()
+
   action = open(test.built_file_path('obj/action.ninja')).read()
   if '..\\..\\out\\Default' in action:
     test.fail_test()
   if '..\\..\\SomethingElse' in action or 'SomethingElse' not in action:
     test.fail_test()
   if '..\\..\\SomeOtherInput' in action or 'SomeOtherInput' not in action:
     test.fail_test()
 
   test.pass_test()