[api] Minor improvement to documentation for kNonMasking.

test/cctest/test-api-interceptors.cc

Index: test/cctest/test-api-interceptors.cc
diff --git a/test/cctest/test-api-interceptors.cc b/test/cctest/test-api-interceptors.cc
index e8a674a1d1fc9144d6da4ffcf4ec683275811d64..e97c0c04058d836311ed59a9d8cdea936bd8b220 100644
--- a/test/cctest/test-api-interceptors.cc
+++ b/test/cctest/test-api-interceptors.cc
@@ -4338,6 +4338,9 @@ THREADED_TEST(NonMaskingInterceptorOwnProperty) {
   ExpectInt32("obj.whatever", 239);
 
   CompileRun("obj.whatever = 4;");
+
+  // obj.whatever exists, thus it is not affected by the non-masking
+  // interceptor.
   ExpectInt32("obj.whatever", 4);
 
   CompileRun("delete obj.whatever;");