Bug 1753836 - Document why ContentDelegateChild doesn't need changes due to the change above. r=agi

Android has no full-page zoom, so we are not meaningfully changing behavior.

However, these values are exposed to the GeckoView JS api, surprisingly, yet
viewport scaling and so on can change the CSS to device pixel ratio...

Shouldn't we expose device pixels there instead? Or do the api consumers assume
that those CSS pixels are scaled to the device scale factor somehow (and that's
not working)?

Depends on D138037

Differential Revision: https://phabricator.services.mozilla.com/D138038

mobile/android/actors/ContentDelegateChild.jsm

@@ -93,6 +93,9 @@ class ContentDelegateChild extends GeckoViewActorChild {
         if (uri || isImage || isMedia) {
           const msg = {
             type: "GeckoView:ContextMenu",
+            // We don't have full zoom on Android, so using CSS coordinates
+            // here is fine, since the CSS coordinate spaces match between the
+            // child and parent processes.
             screenX: aEvent.screenX,
             screenY: aEvent.screenY,
             baseUri: (baseUri && baseUri.displaySpec) || null,