Update

Apparently this is patched out by Brave, but it is enabled by default. See u/[email protected] 's comment below!

Vanilla chromium gives google's websites special treatment by offering detailed CPU info, among other things. This is implemented through a hidden browser extension. You can prove this by yourself by running chrome.runtime.sendMessage("nkeimhogjdpnpccoofpliimaahmaaome", {method: "cpu.getInfo"}, (response) => {console.log(JSON.stringify(response, null, 2)); }, ); on google.com through the browser console. For me, it gives the following info:

 undefined

    
{
  "value": {
    "archName": "x86_64",
    "features": [
      "mmx",
      "sse",
      "sse2",
      "sse3",
      "ssse3",
      "sse4_1",
      "sse4_2",
      "avx"
    ],
    "modelName": "Intel(R) Core(TM) i7-2620M CPU @ 2.70GHz",
    "numOfProcessors": 4,
    "processors": [
      {
        "usage": {
          "idle": 28238205,
          "kernel": 827581,
          "total": 32762960,
          "user": 369