Fix the way to check terminal field in interactive form

Originally the key "T" was checked which was not correct since that
key is optional. Now change to check "FT" as well as its parent's
key since this key is also inheritable.

BUG=chromium:440132

Review-Url: https://codereview.chromium.org/2554223002
diff --git a/DEPS b/DEPS
index 592f5b6..6f89773 100644
--- a/DEPS
+++ b/DEPS
@@ -15,7 +15,7 @@
   'gtest_revision': '8245545b6dc9c4703e6496d1efd19e975ad2b038',
   'icu_revision': '2341038bf72869a5683a893a2b319a48ffec7f62',
   'instrumented_lib_revision': '45f5814b1543e41ea0be54c771e3840ea52cca4a',
-  'pdfium_tests_revision': '943683e198317881f2111e9c55c0bae34b529a33',
+  'pdfium_tests_revision': '9d17ef47f310332ac64e78e636681d493482a409',
   'skia_revision': 'a9fd106d0c4dd5449c607add0716db7bbd81bc73',
   'tools_memory_revision': '427f10475e1a8d72424c29d00bf689122b738e5d',
   'trace_event_revision': '06294c8a4a6f744ef284cd63cfe54dbf61eea290',