Fix GN unit tests

tools/gn/ninja_script_target_writer_unittest.cc

Index: tools/gn/ninja_script_target_writer_unittest.cc
diff --git a/tools/gn/ninja_script_target_writer_unittest.cc b/tools/gn/ninja_script_target_writer_unittest.cc
index 2057f072ce5582970c008f9f776dd48dca148935..f3e7bf13de8cd0baf6919eac5bffbda842921930 100644
--- a/tools/gn/ninja_script_target_writer_unittest.cc
+++ b/tools/gn/ninja_script_target_writer_unittest.cc
@@ -126,9 +126,8 @@ TEST(NinjaScriptTargetWriter, InvokeOverSources) {
     // TODO(brettw) I think we'll need to worry about backslashes here
     // depending if we're on actual Windows or Linux pretending to be Windows.
     const char expected_win[] =
-        "arch = environment.x86\n"
         "rule __foo_bar___rule\n"
-        "  command = C:/python/python.exe gyp-win-tool action-wrapper $arch __foo_bar___rule.$unique_name.rsp\n"
+        "  command = C:/python/python.exe gyp-win-tool action-wrapper environment.x86 __foo_bar___rule.$unique_name.rsp\n"
         "  description = CUSTOM //foo:bar()\n"
         "  restat = 1\n"
         "  rspfile = __foo_bar___rule.$unique_name.rsp\n"