commit 3d8c6cb9cab9cda8e34e82149bc35a41da31150f
author Tobiasz Ciepliński <tobson@google.com> Fri Jul 18 10:50:28 2025
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Fri Jul 18 10:50:28 2025
tree 14f66d96c2442083ff968bb87a78510189043b82
parent b6e9078a3430470edbcd2b7b0ba8b8ae19c11644

Log metrics for synthetic selects during form search in the renderer.

Based on chromium-review.googlesource.com/6448900.

Synthetic selects are select elements that are not built with native
<select> element, but rather use <div>s, <span>s, <button>s etc. with
CSS and JavaScript. This CL adds metrics for assessing the number of
synthetic selects in the web forms. There's no reliable way to classify
an element as a synthetic select. The only way is to apply heuristics to
achieve some level of accuracy.

A potential synthetic select is an element which has:
 * 'aria-expanded' attribute.
 * 'aria-haspopup' attribute.
Such an element is classified as a synthetic select by the heuristic if
1 of the following conditions is true: The element has
 * 'select' substring in the HTML tag name.
 * 'select' substring in the class attribute.
 * 'select' substring in the name attribute.
 * 'role' attribute equal to 'combobox'.
 * 'aria-haspopup' attribute equal to 'listbox'.

For every form the following metrics count the number of synthetic
selects and elements which can potentially be synthetic selects:
 * Autofill.ExtractFormOwned.SyntheticSelectsCount
 * Autofill.ExtractFormOwned.MaybeSyntheticSelectsCount

The list of forms on a HTML web page is maintained by the
TopLevelFormList in the document.cc. Before this CL, the BFS to find all
forms on the page didn't enter the <form> tag. After this CL, every
detected form is traversed to find the number of elements satisfying the
conditions described above.

Bug: 393998600
Change-Id: I7dab2206b83b4eee9b1e8c48e051d5e982e90b38
Validate-Test-Flakiness: skip due to crbug.com/428242626
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6718169
Reviewed-by: Timofey Chudakov <tchudakov@google.com>
Commit-Queue: Dominic Battré <battre@chromium.org>
Reviewed-by: Dominic Battré <battre@chromium.org>
Auto-Submit: Tobiasz Ciepliński <tobson@google.com>
Cr-Commit-Position: refs/heads/main@{#1488746}