Cleanup ios_xctest_test template.

build/config/ios/rules.gni

Index: build/config/ios/rules.gni
diff --git a/build/config/ios/rules.gni b/build/config/ios/rules.gni
index ec8c087fb5319f48a8487ac74bdd9e3e9825cdf1..d6413633829f6fa4be14ab248815c75d75f5c1b7 100644
--- a/build/config/ios/rules.gni
+++ b/build/config/ios/rules.gni
@@ -1270,14 +1270,6 @@ template("ios_xctest_test") {
     _output_name = invoker.output_name
   }
 
-  # TODO(crbug.com/662404): Remove when all downstream uses has been removed.
-  # If the variable is overridden, assert that it is true as all uses should
-  # have set it to true (otherwise changing the default would break things).
-  if (defined(invoker.use_new_naming_convention)) {
-    assert(invoker.use_new_naming_convention,
-           "use_new_naming_convention must be true if defined.")
-  }
-
   _xctest_target = _target_name + "_module"
   _xctest_output = _output_name + "_module"