Required by Twitter to move the input caret of the 2FA <input> element
to the start. However, we don't currently handle individual <input>
element selections.
The intent is to use these to autogenerate prototype declarations for
Window and WorkerGlobalScope classes.
And the spec links are just nice to have :^)
This includes punting on the actual file picker implementation all the
way out to the PageClient. It's likely that some of the real details
should be implemented somewhere closer, like the BrowsingContext or the
Page, but we'll get there.
For now, this allows https://copy.sh/v86 to load the emulation of the
preselected images all the way until it hits a call to
URL.createObjectURL.
HTMLInputElement now inherits from FormAssociatedElement, which will
be a common base for the handful of elements that need to track their
owner form (and register with it for the form.elements collection.)
At the moment, the owner form is assigned during DOM insertion/removal
of an HTMLInputElement. I didn't implement any of the legacy behaviors
defined by the HTML parsing spec yet.
Text <input> fields will now generate a basic shadow DOM and attach it
to the input element.
The shadow DOM contains a <div> with some inline style, and an always-
editable text node inside it. Accessing the "value" attribute on such
an input element will get/set the value from that text node.
This is really cool, although not super stable since HTML editing is
not super stable. But it's a start! :^)
