Bug 1875100 - Propagate top level activeness automatically to top descendants. r=nika,tabbrowser-reviewers,mconley,extension-reviewers,robwu,geckoview-reviewers,owlish

For that, opt in tabbrowser and the shopping sidebar to manual
activeness management.

Differential Revision: https://phabricator.services.mozilla.com/D198942

browser/base/content/test/fullscreen/FullscreenFrame.sys.mjs

@@ -43,7 +43,6 @@ export class FullscreenFrameChild extends JSWindowActorChild {
       case "ExitFullscreen":
         return this.contentWindow.document.exitFullscreen();
       case "RequestFullscreen":
-        this.browsingContext.isActive = true;
         return Promise.all([this.changed(), this.requestFullscreen()]);
       case "CreateChild":
         let child = msg.data;