password_field_prediction.cc: More info for TODO

This just adds a link to a crbug.com comment with some thoughts about
solutions to a TODO comment inside password_field_prediction.cc.

TBR-ing Vadym, because this is a comment-only minor change.
TBR=dvadym@chromium.org

Bug: 853149
Change-Id: Id71691e9abff7cb19d069b9de30eef5c4a64fe11
Reviewed-on: https://chromium-review.googlesource.com/1102683Reviewed-by: Vaclav Brozek <vabr@chromium.org>
Commit-Queue: Vaclav Brozek <vabr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567704}

components/password_manager/core/browser/form_parsing/password_field_prediction.cc

@@ -47,7 +47,8 @@ FormPredictions ConvertToFormPredictions(const FormData& observed_form,
   DCHECK_EQ(observed_form.fields.size(), form_structure.field_count());
   FormPredictions result;
   if (observed_form.fields.size() != form_structure.field_count()) {
-    // TODO(https://crbug.com/831123). Find the reason why this can happen.
+    // TODO(https://crbug.com/831123). Find the reason why this can happen. See
+    // https://crbug.com/853149#c6 for some ideas.
     return result;
   }
   for (size_t i = 0; i < observed_form.fields.size(); ++i) {