[DevTools Bug]: High CPU usage when viewing Google Search results

### Website or app https://www.google.com/search?client=firefox-b-d&q=sociale+huur+samenwonen ### Repro steps I noticed my fans started whining, so I looked into the system monitor for the cause. The cause was firefox and the webextensions process. Looking into the firefox task manager, it showed a google tab and extensons being high. Profiling using the debugger (pausing then pressing play again multiple times and looking what places are executed), showed this extension and some script (that handled `message` events) on google.com as the cause. Debugging using `window.addEventListener('message', (e) => console.log(e))` showed the following spam repeated: ``` message { target: Window, isTrusted: true, data: {…}, origin: "https://www.google.com", lastEventId: "", source: Window, ports: Restricted, srcElement: Window, currentTarget: Window, eventPhase: 2, … } ​ bubbles: false ​ cancelBubble: false ​ cancelable: false ​ composed: false ​ currentTarget: null ​ data: Object { source: "react-devtools-content-script", hello: true } ​ defaultPrevented: false ​ eventPhase: 0 ​ explicitOriginalTarget: Window https://www.google.com/search?client=firefox-b-d&q=sociale+huur+samenwonen ​ isTrusted: true ​ lastEventId: "" ​ origin: "https://www.google.com" ​ originalTarget: Window https://www.google.com/search?client=firefox-b-d&q=sociale+huur+samenwonen ​ ports: Array [] ​ returnValue: true ​ source: Window https://www.google.com/search?client=firefox-b-d&q=sociale+huur+samenwonen ​ srcElement: Window https://www.google.com/search?client=firefox-b-d&q=sociale+huur+samenwonen ​ target: Window https://www.google.com/search?client=firefox-b-d&q=sociale+huur+samenwonen ​ timeStamp: 536381 ​ type: "message" ​ <get isTrusted()>: function isTrusted() ​ <prototype>: MessageEventPrototype { initMessageEvent: initMessageEvent(), data: Getter, origin: Getter, … } ​​ constructor: function MessageEvent() ​​ data: ​​ initMessageEvent: function initMessageEvent() ​​ lastEventId: ​​ origin: …