Add support for modifier keys in test_driver.send_keys()

[Manuel Rego Casasnovas]

There's a FIXME about that in LayoutTests/imported/w3c/web-platform-tests/resources/testdriver-vendor.js (https://webkit-search.igalia.com/webkit/source/LayoutTests/imported/w3c/web-platform-tests/resources/testdriver-vendor.js#158):
    // FIXME: Add the support for modifier keys.

This causes that we cannot do things like test_driver.send_keys(element, "\uE009" + "Y") (Ctrl + Y).

Chromium supports this with the following code: https://source.chromium.org/chromium/chromium/src/+/master:third_party/blink/web_tests/resources/testdriver-vendor.js;l=100?q=testdriver-vendor.js

[Manuel Rego Casasnovas]

Created attachment 419720 [details]
Patch

[EWS Watchlist]

This patch modifies the imported WPT tests. Please ensure that any changes on the tests (not coming from a WPT import) are exported to WPT. Please see https://trac.webkit.org/wiki/WPTExportProcess

[Manuel Rego Casasnovas]

Created attachment 419827 [details]
Patch

[Manuel Rego Casasnovas]

Created attachment 419828 [details]
Patch

[Manuel Rego Casasnovas]

Created attachment 419829 [details]
Patch

[Manuel Rego Casasnovas]

Created attachment 419831 [details]
Patch

[Manuel Rego Casasnovas]

The EWSs are green now and the WPT test passes in Chromium and Firefox.
I believe this is ready to be reviewed. Please take a look, thanks!

[Sam Sneddon [:gsnedders]]

Comment on attachment 419831 [details]
Patch

(non-reviewer r+)

[EWS]

Committed r272651: <https://commits.webkit.org/r272651>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 419831 [details].

[Radar WebKit Bug Importer]

<rdar://problem/74187704>