Add an autofill module

index.bs

@@ -80,6 +80,7 @@ spec: WEBDRIVER; urlPrefix: https://w3c.github.io/webdriver/
     text: input cancel list; url: dfn-input-cancel-list
     text: intermediary node; url: dfn-intermediary-node
     text: invalid argument; url: dfn-invalid-argument
+    text: invalid element state; url: dfn-invalid-element-state
     text: invalid selector; url: dfn-invalid-selector
     text: invalid session id; url: dfn-invalid-session-id
     text: is element origin; url: dfn-is-element-origin
@@ -188,6 +189,7 @@ spec: HTML; urlPrefix: https://html.spec.whatwg.org/multipage/
     text: close; url: window-object.html#close-a-browsing-context
     text: disabled; url: form-control-infrastructure.html#concept-fe-disabled
     text: File Upload state; url: input.html#file-upload-state-(type=file)
+    text: form-associated element; url: forms.html#form-associated-element
     text: confirm; url: timers-and-user-prompts.html#dom-confirm
     text: context mode; url: /canvas.html#offscreencanvas-context-mode
     text: create a classic script; url: webappapis.html#creating-a-classic-script
@@ -282,6 +284,9 @@ spec: CORE-AAM; urlPrefix:https://www.w3.org/TR/core-aam-1.2
 spec: MEDIAQUERIES4; urlPrefix: https://drafts.csswg.org/mediaqueries-4/
   type: dfn
     text: resolution media feature; url: #resolution
+spec:infra; urlPrefix: https://infra.spec.whatwg.org/
+  type:dfn;
+    text:user agent
 </pre>
 
 <pre class="biblio">
@@ -632,6 +637,7 @@ with the following additional codes:
 <pre class="cddl local-cddl">
 ErrorCode = "invalid argument" /
             "invalid selector" /
+            "invalid element state" /
             "invalid session id" /
             "move target out of bounds" /
             "no such alert" /
@@ -10651,6 +10657,155 @@ The [=remote end steps=] given |session| and |command parameters| are:
 
 </div>
 
+## The autofill Module ## {#module-autofill}
+
+The <dfn export for=modules>autofill</dfn> module contains functionality for
+saving and triggering autofill.
+
+A [=/browsing context=] has a <dfn>autofill store for testing</dfn>, an
+<a>ordered map</a>.
+
+### Definition ### {#module-autofill-definition}
+
+[=remote end definition=]
+
+<pre class="cddl remote-cddl">
+
+InputCommand = (
+  autofill.save //
+  autofill.trigger
+)
+</pre>
+
+### Commands ### {#module-autofill-commands}
+
+#### The autofill.save Command ####  {#command-autofill-save}
+
+The <dfn export for=commands>autofill.save</dfn> command saves a set of field
+name values to the [=/browsing context=]'s [=autofill store for testing=].
+
+<dl>
+   <dt>Command Type</dt>
+   <dd>
+    <pre class="cddl remote-cddl">
+      autofill.save = (
+        method: "autofill.save",
+        params: autofill.saveParameters
+      )
+
+      autofill.saveParameters = {
+        context: browsingContext.BrowsingContext,
+        fields: [*autofill.field]
+      }
+
+      autofill.field = (
+        name: tstr,
+        value: tstr
+      )
+    </pre>
+   </dd>
+   <dt>Return Type</dt>
+   <dd>
+    <pre class="cddl">
+     EmptyResult
+    </pre>
+   </dd>
+</dl>
+
+<div algorithm="remote end steps for autofill.save">
+
+The [=remote end steps=] with <var ignore="">session</var> and
+|command parameters| are:
+
+1. Let |context id| be the value of the <code>context</code> field of
+   |command parameters|.
+
+1. Let |context| be the result of [=trying=] to [=get a browsing context=]
+   with |context id|.
+
+1. Let |store| be |context|'s [=autofill store for testing=].
+
+1. Let |fields| be the value of the <code>fields</code> field of |command
+   parameters|.
+
+1. For each |field| in |fields|:
+
+   1. Let |name| be |field|'s <code>name</code>.
+
+   1. Let |value| be |field|'s <code>value</code>.
+
+   1. Set |store|[|name|] to |value|.
+
+1. Return [=success=] with data null.
+
+</div>
+
+#### The autofill.trigger Command ####  {#command-autofill-trigger}
+
+The <dfn export for=commands>autofill.trigger</dfn> command triggers autofill
+on a particular form field using the [=/browsing context=]'s [=autofill
+store for testing=].
+
+<dl>
+   <dt>Command Type</dt>
+   <dd>
+    <pre class="cddl remote-cddl">
+      autofill.trigger = (
+        method: "autofill.trigger",
+        params: autofill.triggerParameters
+      )
+
+      autofill.triggerParameters = {
+        context: browsingContext.BrowsingContext,
+        element: script.SharedReference
+      }
+    </pre>
+   </dd>
+   <dt>Return Type</dt>
+   <dd>
+    <pre class="cddl">
+     EmptyResult
+    </pre>
+   </dd>
+</dl>
+
+<div algorithm="remote end steps for autofill.trigger">
+
+The [=remote end steps=] with |session| and |command parameters| are:
+
+1. Let |context id| be the value of the <code>context</code> field of
+   |command parameters|.
+
+1. Let |context| be the result of [=trying=] to [=get a browsing context=]
+   with |context id|.
+
+1. Let |document| be |context|'s [=active document=].
+
+1. Let |environment settings| be the [=environment settings object=] whose
+   [=relevant global object=]'s <a>associated <code>Document</code></a> is
+   |document|.
+
+1. Let |realm| be |environment settings|' [=realm execution context=]'s
+  Realm component.
+
+1. Let |element id| be the value of the <code>element</code> field of
+   |command parameters|.
+
+1. Let |element| be the result of [=trying=] to [=deserialize remote reference=]
+   with the |element id|, |realm|, and |session|.
+
+1. Let |store| be |context|'s [=autofill store for testing=].
+
+1. If |element| is not a [=form-associated element=] or |element|'s [=form owner=] is
+   null, return an [=error=] with [=error code=] [=invalid element state=].
+
+1. The [=user agent=] should [=autofill=] |element| and |element|'s [=form
+   owner=], while taking into account the contents of |store|.
+
+1. Return [=success=] with data null.
+
+</div>
+
 # Patches to Other Specifications # {#patches}
 
 This specification requires some changes to external specifications to provide the necessary