Move gn _run target generation into test().

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index d1c58755b3d40bf5aea3b3aa6dd9856ae0259f30..61cd4dd715a514a20840ebbd07b82d468c916a6b 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -462,8 +462,8 @@ group("both_gn_and_gyp") {
         # TODO(dpranke): Figure out what platforms should actually have this.
         deps += [
           "//components/nacl/loader:helper_nonsfi",
-          "//components/nacl/loader:helper_nonsfi_unittests",
           "//components/nacl/loader:nacl_helper",
+          "//components/nacl/loader:nacl_helper_nonsfi_unittests",
         ]
       }
     }