Previously the `<input type=file>` would wait synchronously for file
selection
results from the embedder. This change moves that synchronous wait to
the
`FileManager` worker thread. The main benefit is that script is not
blocked waiting
for the embedder. The synchronous wait on the worker thread is not a
large issue
because it is run from a thread pool, though a later change could also
remove
that synchronous wait.
In addition, the API surface for file selection changes a bit as there
is now a `dismiss`
method which differentiates between selecting no file and not making a
choice at
all.
Testing: Covered by exiting WPT, WebDriver conformance, and unit tests.
---------
Signed-off-by: delan azabani <dazabani@igalia.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Martin Robinson <mrobinson@igalia.com>