Use same origin checks instead of same origin-domain ones (#236)

From different sources [1][2][3], it looks like same origin-domain is not anymore recommended.
There is no obvious reason to keep same origin-domain in compute pressure specifications.
Instead same origin seems to be a better security check.

[1] https://html.spec.whatwg.org/multipage/browsers.html#relaxing-the-same-origin-restriction
[2] https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/platform/weborigin/security_origin.h;l=313;drc=933be5e5db24585647edcd7f507ba2d48c5757c8
[3] https://dontcallmedom.github.io/webdex/s.html

Fixes #187

index.html

@@ -881,7 +881,7 @@ <h3>Supporting algorithms</h3>
             they are <a href="https://html.spec.whatwg.org/multipage/workers.html#active-needed-worker">active needed workers</a>.
           </li>
           <li>
-            Their [=origin=] is [=same origin-domain=] with the [=Node/node document|document=] containing the
+            Their [=origin=] is [=same origin=] with the [=Node/node document|document=] containing the
             <a href="https://html.spec.whatwg.org/multipage/interaction.html#focused">focused</a> [=node=], or an
             <a href="https://w3c.github.io/picture-in-picture/#initiators-of-active-picture-in-picture-sessions">
             initiator of an active Picture-in-Picture session</a>, or the browsing [=context is capturing=],
@@ -916,7 +916,7 @@ <h3>Supporting algorithms</h3>
                 initiators of active Picture-in-Picture sessions</a>:
               <ol>
                 <li>
-                  If |relevantGlobal|'s [=relevant settings object=]'s [=origin=] is [=same origin-domain=] with |origin|, return true.
+                  If |relevantGlobal|'s [=relevant settings object=]'s [=origin=] is [=same origin=] with |origin|, return true.
                 </li>
               </ol>
             </li>
@@ -935,7 +935,7 @@ <h3>Supporting algorithms</h3>
                 currently focused area</a>'s [=Node/node document=].
             </li>
             <li>
-              If |relevantGlobal|'s [=relevant settings object=]'s [=origin=] is [=same origin-domain=] with
+              If |relevantGlobal|'s [=relevant settings object=]'s [=origin=] is [=same origin=] with
               |focusedDocument|'s [=origin=], return true.
             </li>
             <li>