Add TODO in genreate_origin_trial_features.py about includes in mixin idl

Bug: 1061995
Change-Id: I9e2e5ca1ba35e979ce2976ea4a722fcee2570f33
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2104013
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Majid Valipour <majidvp@chromium.org>
Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#750645}

third_party/blink/renderer/bindings/scripts/generate_origin_trial_features.py

@@ -100,6 +100,8 @@ def origin_trial_features_info(info_provider, reader, idl_filenames,
 
         # If this interface is a mixin, we don't generate V8 bindings code for
         # it.
+        # TODO(crbug.com/1061995): This incorrectly ignores includes in the
+        # mixin idl like "SomeInterface includes MixinInterface".
         if interface.is_mixin:
             continue