Editorial: prepare create a notification for Declarative Web Push

This makes the following changes:

- Instead of making create a notification deal directly with a service worker registration, we leave that to the callers. We also make service worker registration always present on a notification as "can have" fields are confusing and buggy.
- Stop requiring an environment settings object for create a notification as that won't necessarily be around for Declarative Web Push.
- Sprinkle some `<div algorithm>` around to reduce variable errors and make variables easier to track in user agents with JavaScript enabled.

Author: annevk

notifications.bs

@@ -42,8 +42,9 @@ IDL, Service Workers, URL, and Vibration API Standards.
 <p>A <dfn id=concept-notification>notification</dfn> is an abstract
 representation of something that happened, such as the delivery of a message.
 
-<p>A <a>notification</a> <em>can</em> have an associated
-<dfn for=notification id=service-worker-registration>service worker registration</dfn>.
+<p>A <a>notification</a> has an associated
+<dfn for=notification id=service-worker-registration>service worker registration</dfn> (null
+or a <a for=/>service worker registration</a>). It is initially null.
 
 <p>A <a>notification</a> has an associated
 <dfn for=notification id=concept-title>title</dfn> which is a string.
@@ -156,35 +157,45 @@ corners or painting it in a specific color. Developers are encouraged to use an
 such cases gracefully and does not lose important information through, e.g., loss of color or
 clipped corners.
 
-<p>A <dfn>non-persistent notification</dfn> is a
-<a>notification</a> without an associated
-<a for=notification>service worker registration</a>.
+<p>A <dfn>non-persistent notification</dfn> is a <a>notification</a> whose
+<a for=notification>service worker registration</a> is null.
 
-<p>A <dfn>persistent notification</dfn> is a
-<a>notification</a> with an associated
-<a for=notification>service worker registration</a>.
+<p>A <dfn>persistent notification</dfn> is a <a>notification</a> whose
+<a for=notification>service worker registration</a> is non-null.
 
 <!-- XXX https://html.spec.whatwg.org/#fingerprinting-vector -->
 
 <hr>
 
-<p>To <dfn lt="create a notification|creating a notification">create a notification</dfn>, given a
-string <var>title</var>, {{NotificationOptions}} <a for=/>dictionary</a> <var>options</var>,
-<a for=/>environment settings object</a> <var>settings</var>, and optionally a
-{{ServiceWorkerRegistration}} object <var>serviceWorkerRegistration</var>, run these steps:
+<div algorithm>
+<p>To <dfn>create a notification with a settings object</dfn>, given a string <var>title</var>,
+{{NotificationOptions}} <a for=/>dictionary</a> <var>options</var>, and
+<a for=/>environment settings object</a> <var>settings</var>:
 
 <ol>
- <li><p>Let <var>notification</var> be a new <a>notification</a>.
+ <li><p>Let <var>origin</var> be <var>settings</var>'s
+ <a for="environment settings object">origin</a>.
+
+ <li><p>Let <var>baseURL</var> be <var>settings</var>'s
+ <a for="environment settings object">API base URL</a>.
 
- <li><p>If a <var>serviceWorkerRegistration</var> was provided, then set <var>notification</var>'s
- <a for=notification>service worker registration</a> to <var>serviceWorkerRegistration</var>.
+ <li><p>Let <var>fallbackTimestamp</var> be the number of milliseconds from the <a>Unix epoch</a> to
+ <var>settings</var>'s <a for="environment settings object">current wall time</a>, rounded to the
+ nearest integer.
 
- <li>
-  <p>If a <var>serviceWorkerRegistration</var> was not provided and
-  <var>options</var>["{{NotificationOptions/actions}}"] is not <a for=list>empty</a>, then
-  <a>throw</a> a {{TypeError}}.
+ <li><p>Return the result of <a>creating a notification</a> given <var>title</var>,
+ <var>options</var>, <var>origin</var>, <var>baseURL</var>, and <var>fallbackTimestamp</var>.
+</ol>
+</div>
 
-  <p class=note><a>Actions</a> are only currently supported for <a>persistent notifications</a>.
+<div algorithm>
+<p>To <dfn export>create a notification</dfn>, given a string <var>title</var>,
+{{NotificationOptions}} <a for=/>dictionary</a> <var>options</var>, an <a for=/>origin</a>
+<var>origin</var>, a <a for=/>URL</a> <var>baseURL</var>, and an {{EpochTimeStamp}}
+<var>fallbackTimestamp</var>:
+
+<ol>
+ <li><p>Let <var>notification</var> be a new <a>notification</a>.
 
  <li><p>If <var>options</var>["{{NotificationOptions/silent}}"] is true and
  <var>options</var>["{{NotificationOptions/vibrate}}"] <a for=map>exists</a>, then <a>throw</a> a
@@ -205,18 +216,14 @@ string <var>title</var>, {{NotificationOptions}} <a for=/>dictionary</a> <var>op
  <li><p>Set <var>notification</var>'s <a for=notification>language</a> to
  <var>options</var>["{{NotificationOptions/lang}}"].
 
- <li><p>Set <var>notification</var>'s <a for=notification>origin</a> to <var>settings</var>'s
- <a for="environment settings object">origin</a>.
+ <li><p>Set <var>notification</var>'s <a for=notification>origin</a> to <var>origin</var>.
 
  <li><p>Set <var>notification</var>'s <a for=notification>body</a> to
  <var>options</var>["{{NotificationOptions/body}}"].
 
  <li><p>Set <var>notification</var>'s <a for=notification>tag</a> to
  <var>options</var>["{{NotificationOptions/tag}}"].
 
- <li><p>Let <var>baseURL</var> be <var>settings</var>'s
- <a for="environment settings object">API base URL</a>.
-
  <li><p>If <var>options</var>["{{NotificationOptions/image}}"] <a for=map>exists</a>, then
  <a lt="URL parser">parse</a> it using <var>baseURL</var>, and if that does not return failure, set
  <var>notification</var>'s <a>image URL</a> to the return value. (Otherwise
@@ -238,9 +245,7 @@ string <var>title</var>, {{NotificationOptions}} <a for=/>dictionary</a> <var>op
 
  <li><p>If <var>options</var>["{{NotificationOptions/timestamp}}"] <a for=map>exists</a>, then set
  <var>notification</var>'s <a for=notification>timestamp</a> to the value. Otherwise, set
- <var>notification</var>'s <a for=notification>timestamp</a> to the number of milliseconds from the
- <a>Unix epoch</a> to <var>settings</var>'s
- <a for="environment settings object">current wall time</a>, rounded to the nearest integer.
+ <var>notification</var>'s <a for=notification>timestamp</a> to <var>fallbackTimestamp</var>.
 
  <li><p>Set <var>notification</var>'s <a for=notification>renotify preference</a> to
  <var>options</var>["{{NotificationOptions/renotify}}"].
@@ -276,6 +281,7 @@ string <var>title</var>, {{NotificationOptions}} <a for=/>dictionary</a> <var>op
 
  <li><p>Return <var>notification</var>.
 </ol>
+</div>
 
 
 <h3 id=lifetime-and-ui-integrations>Lifetime and UI integration</h3>
@@ -692,6 +698,7 @@ object and can be created through {{Notification}}'s
 
 <h3 id=constructors>Constructors</h3>
 
+<div algorithm>
 <p>The
 <dfn constructor for=Notification lt="Notification(title, options)"><code>new Notification(<var>title</var>, <var>options</var>)</code></dfn>
 constructor steps are:
@@ -700,8 +707,15 @@ constructor steps are:
  <li><p>If <a>this</a>'s <a>relevant global object</a> is a {{ServiceWorkerGlobalScope}} object,
  then <a>throw</a> a {{TypeError}}.
 
- <li><p>Let <var>notification</var> be the result of <a>creating a notification</a> given
- <var>title</var>, <var>options</var>, and <a>this</a>'s <a>relevant settings object</a>.
+ <li>
+  <p>If <var>options</var>["{{NotificationOptions/actions}}"] is not <a for=list>empty</a>, then
+  <a>throw</a> a {{TypeError}}.
+
+  <p class=note><a>Actions</a> are only supported for <a>persistent notifications</a>.
+
+ <li><p>Let <var>notification</var> be the result of
+ <a>creating a notification with a settings object</a> given <var>title</var>, <var>options</var>,
+ and <a>this</a>'s <a>relevant settings object</a>.
 
  <li><p>Associate <a>this</a> with <var>notification</var>.
 
@@ -718,12 +732,15 @@ constructor steps are:
    <li><p>Run the <a>show steps</a> for <var>notification</var>.
   </ol>
 </ol>
+</div>
 
 
 <h3 id=static-members>Static members</h3>
 
+<div algorithm>
 <p>The static <dfn attribute for=Notification><code>permission</code></dfn> getter steps are to
 return the result of <a>getting the notifications permission state</a>.
+</div>
 
 <div class=note>
  <p>If you edit standards please refrain from copying the above. Synchronous permissions are like
@@ -740,6 +757,7 @@ return the result of <a>getting the notifications permission state</a>.
  </pre>
 </div>
 
+<div algorithm>
 <p>The static
 <dfn method for=Notification><code>requestPermission(<var>deprecatedCallback</var>)</code></dfn>
 method steps are:
@@ -770,6 +788,7 @@ method steps are:
 
  <li><p>Return <var>promise</var>.
 </ol>
+</div>
 
 <p class="warning">Notifications are the one instance thus far where asking the end user upfront
 makes sense. Specifications for other APIs should not use this pattern and instead employ one of the
@@ -1029,7 +1048,9 @@ partial interface ServiceWorkerGlobalScope {
 };
 </pre>
 
-<p>The <dfn method for=ServiceWorkerRegistration><code>showNotification(title, options)</code></dfn>
+<div algorithm>
+<p>The
+<dfn method for=ServiceWorkerRegistration><code>showNotification(<var>title</var>, <var>options</var>)</code></dfn>
 method steps are:
 
 <ol>
@@ -1042,12 +1063,13 @@ method steps are:
  <!-- We might have to throw directly here and below, see
       https://github.com/web-platform-tests/wpt/pull/24601 -->
 
- <li><p>Let <var>serviceWorkerRegistration</var> be <a>this</a>.
+ <li><p>Let <var>notification</var> be the result of
+ <a>creating a notification with a settings object</a> given <var>title</var>, <var>options</var>,
+ and <a>this</a>'s <a>relevant settings object</a>. If this threw an exception, then
+ <a for=/>reject</a> <var>promise</var> with that exception and return <var>promise</var>.
 
- <li><p>Let <var>notification</var> be the result of <a>creating a notification</a> given
- <var>title</var>, <var>options</var>, <a>this</a>'s <a>relevant settings object</a>, and
- <var>serviceWorkerRegistration</var>. If this threw an exception, then <a for=/>reject</a>
- <var>promise</var> with that exception and return <var>promise</var>.
+ <li><p>Set <var>notification</var>'s <a for=notification>service worker registration</a> to
+ <a>this</a>.
 
  <li>
   <p>Run these steps <a>in parallel</a>:
@@ -1068,7 +1090,9 @@ method steps are:
 
  <li><p>Return <var>promise</var>.
 </ol>
+</div>
 
+<div algorithm>
 <p>The
 <dfn method for=ServiceWorkerRegistration><code>getNotifications(<var>filter</var>)</code></dfn>
 method steps are:
@@ -1116,26 +1140,34 @@ method steps are:
 
 <p class=note>This method returns zero or more new {{Notification}} objects which might represent
 the same underlying <a>notification</a> of {{Notification}} objects already in existence.
+</div>
 
 <hr>
 
-<p>To <dfn>fire a service worker notification event</dfn> named <var>name</var> given
-<var>notification</var> (a <a>notification</a>), and an optional <var>action</var> (a DOMString,
-defaulting to the empty string), <a>Fire Functional Event</a> <var>name</var> using
-{{NotificationEvent}} on <var>notification</var>'s
-<a for=notification>service worker registration</a> with the following properties:
+<div algorithm>
+<p>To <dfn>fire a service worker notification event</dfn> named <var>name</var> given a
+<a for=/>notification</a> <var>notification</var>, and an optional string <var>action</var> (default
+the empty string): run <a>Fire Functional Event</a> given <var>name</var>, {{NotificationEvent}},
+<var>notification</var>'s <a for=notification>service worker registration</a>, and the following
+initialization:
 
 <dl>
  <dt>{{NotificationEvent/notification}}
  <dd>A new {{Notification}} object representing <var>notification</var>.
  <dt>{{NotificationEvent/action}}
  <dd><var>action</var>
 </dl>
+</div>
 
-<p>The {{NotificationEvent/notification}} getter steps are to return the value it was initialized
-to.
+<div algorithm>
+<p>The <dfn attribute for=NotificationEvent><code>notification</code></dfn> getter steps are to
+return the value it was initialized to.
+</div>
 
-<p>The {{NotificationEvent/action}} getter steps are to return the value it was initialized to.
+<div algorithm>
+<p>The <dfn attribute for=NotificationEvent><code>action</code></dfn> getter steps are to return the
+value it was initialized to.
+</div>
 
 <p>The following is the <a>event handler</a> (and its corresponding
 <a>event handler event type</a>) that must be supported as attribute by the