Fix missing variable MSVS expansion of copies arguments with Ninja.

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

Index: test/ninja/normalize-paths-win/gyptest-normalize-paths.py
diff --git a/test/ninja/normalize-paths-win/gyptest-normalize-paths.py b/test/ninja/normalize-paths-win/gyptest-normalize-paths.py
index af48d071cf90594beea585c29e11c09a5b1b06ef..f56dbe5921e2e896c55d363e323c59d7f6180159 100644
--- a/test/ninja/normalize-paths-win/gyptest-normalize-paths.py
+++ b/test/ninja/normalize-paths-win/gyptest-normalize-paths.py
@@ -31,6 +31,10 @@ if sys.platform == 'win32':
       'AnotherName.exe' not in second):
     test.fail_test()
 
+  copytarget = open(test.built_file_path('obj/copy_target.ninja')).read()
+  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()