Use new GN features in the build.

chrome/test/base/js2gtest.gni

Index: chrome/test/base/js2gtest.gni
diff --git a/chrome/test/base/js2gtest.gni b/chrome/test/base/js2gtest.gni
index 35f142f6a63294c7a7947a2a1cf79acb3c32dcb4..4b1dc5f5dbc74722da2bdd36345e2a1b118cb6d2 100644
--- a/chrome/test/base/js2gtest.gni
+++ b/chrome/test/base/js2gtest.gni
@@ -82,13 +82,12 @@ template("js2gtest") {
 
   source_set(source_set_name) {
     testonly = true
-    if (defined(invoker.visibility)) {
-      visibility = invoker.visibility
-    }
+    forward_variables_from(invoker,
+                           [
+                             "defines",
+                             "visibility",
+                           ])
     sources = get_target_outputs(":$action_name")
-    if (defined(invoker.defines)) {
-      defines = invoker.defines
-    }
     deps = [
       ":$action_name",