Restore data: URL matching for shared workers via constructor storage key

When the shared worker lookup was changed to compare storage keys
(5aa1a59), the SharedWorkerGlobalScope constructor origin comparison was
dropped. The replacement derived the worker storage key from the worker's
own settings object, but a data: URL worker has a unique opaque origin, so
its storage key could never equal the creating environment's. This meant a
data: URL shared worker could never be found and reused, even by the page
that created it, and it left the constructor origin concept referenced only
by a now-inaccurate note.

Replace the constructor origin concept with a constructor storage key,
initialized from the creating environment's storage key, and compare that
against the outside storage key during lookup. This restores data: URL
reuse while respecting storage key partitioning (origin and top-level
site), and fixes the note.

Author: annevk

source

@@ -135088,12 +135088,13 @@ interface <dfn interface>SharedWorkerGlobalScope</dfn> : <span>WorkerGlobalScope
 
   <div w-nodev>
 
-  <p>A <code>SharedWorkerGlobalScope</code> object has associated <dfn
-  data-x="concept-SharedWorkerGlobalScope-constructor-origin">constructor origin</dfn> (an
-  <span>origin</span>), <dfn data-x="concept-SharedWorkerGlobalScope-constructor-url">constructor
-  URL</dfn> (a <span>URL record</span>), and <dfn
-  data-x="concept-SharedWorkerGlobalScope-credentials">credentials</dfn> (a <span
-  data-x="concept-request-credentials-mode">credentials mode</span>), and <dfn
+  <p id="concept-sharedworkerglobalscope-constructor-origin">A <code>SharedWorkerGlobalScope</code>
+  object has associated <dfn
+  data-x="concept-SharedWorkerGlobalScope-constructor-storage-key">constructor storage key</dfn> (a
+  <span>storage key</span>), <dfn
+  data-x="concept-SharedWorkerGlobalScope-constructor-url">constructor URL</dfn> (a <span>URL
+  record</span>), and <dfn data-x="concept-SharedWorkerGlobalScope-credentials">credentials</dfn> (a
+  <span data-x="concept-request-credentials-mode">credentials mode</span>), and <dfn
   data-x="concept-SharedWorkerGlobalScope-extended-lifetime">extended lifetime</dfn> (a boolean).
   They are initialized when the <code>SharedWorkerGlobalScope</code> object is created, in the
   <span>run a worker</span> algorithm.</p>
@@ -135502,9 +135503,9 @@ interface <dfn interface>SharedWorkerGlobalScope</dfn> : <span>WorkerGlobalScope
 
     <ol>
      <li><p>Set <var>worker global scope</var>'s <span
-     data-x="concept-SharedWorkerGlobalScope-constructor-origin">constructor origin</span> to
-     <var>outside settings</var>'s <span
-     data-x="concept-settings-object-origin">origin</span>.</p></li>
+     data-x="concept-SharedWorkerGlobalScope-constructor-storage-key">constructor storage key</span>
+     to the result of running <span>obtain a storage key for non-storage purposes</span> given
+     <var>outside settings</var>.</p></li>
 
      <li><p>Set <var>worker global scope</var>'s <span
      data-x="concept-SharedWorkerGlobalScope-constructor-url">constructor URL</span> to
@@ -136224,15 +136225,13 @@ dictionary <dfn dictionary>SharedWorkerOptions</dfn> : <span>WorkerOptions</span
       <code>SharedWorkerGlobalScope</code> objects:</p>
 
       <ol>
-        <li><p>Let <var>workerStorageKey</var> be the result of running <span>obtain a storage key
-        for non-storage purposes</span> given <var>scope</var>'s <span>relevant settings
-        object</span>.</p></li>
-
         <li>
          <p>If all of the following are true:</p>
 
          <ul>
-          <li><var>workerStorageKey</var> <span data-x="storage key equal">equals</span>
+          <li><var>scope</var>'s <span
+          data-x="concept-SharedWorkerGlobalScope-constructor-storage-key">constructor storage
+          key</span> <span data-x="storage key equal">equals</span>
           <var>outsideStorageKey</var>;</li>
 
           <li><var>scope</var>'s <span data-x="dom-WorkerGlobalScope-closing">closing</span> flag is
@@ -136257,12 +136256,14 @@ dictionary <dfn dictionary>SharedWorkerOptions</dfn> : <span>WorkerOptions</span
       </ol>
 
       <p class="note"><code data-x="data protocol">data:</code> URLs create a worker with an <span
-      data-x="concept-origin-opaque">opaque origin</span>. Both the <span
-      data-x="concept-SharedWorkerGlobalScope-constructor-origin">constructor origin</span> and
-      <span data-x="concept-SharedWorkerGlobalScope-constructor-url">constructor URL</span> are
-      compared so the same <code data-x="data protocol">data:</code> URL can be used within an
-      <span>origin</span> to get to the same <code>SharedWorkerGlobalScope</code> object, but cannot
-      be used to bypass the <span>same origin</span> restriction.</p>
+      data-x="concept-origin-opaque">opaque origin</span>, which would prevent such a worker from
+      ever being matched if its own <span>storage key</span> were used. Instead, the <span
+      data-x="concept-SharedWorkerGlobalScope-constructor-storage-key">constructor storage
+      key</span> (derived from the creating environment) and <span
+      data-x="concept-SharedWorkerGlobalScope-constructor-url">constructor URL</span> are compared,
+      so the same <code data-x="data protocol">data:</code> URL can be used within a <span>storage
+      key</span> to get to the same <code>SharedWorkerGlobalScope</code> object, but cannot be used
+      to bypass the <span>storage key</span> restriction.</p>
      </li>
 
      <li>