Fix Brave browser hit canvas support

[techniq]

Due to the Brave browser modifying how getImageData works to provide fingerprinting protection by modifying one of the color channels, we'll need to refine the rgbColorGenerator to provide safer colors.

[techniq]

Changing from ...

export function* rgbColorGenerator(step = 500) {
  let nextColor = 0;

  while (nextColor < 16777216) {
    const r = nextColor & 0xff;
    const g = (nextColor & 0xff00) >> 8;
    const b = (nextColor & 0xff0000) >> 16;

    nextColor += step;
    yield { r, g, b, a: 255 };
  }

  return { r: 0, g: 0, b: 0, a: 255 };
}

to..

export function* rgbColorGenerator(step = 200) {
  let nextColor = 0;

  while (nextColor < (1 << 21)) {
    const r = (nextColor & 0x7f;
    const g = (nextColor >> 7) & 0x7F
    const b = (nextColor >> 14) & 0x7F;

    nextColor += step;
    yield { r: r * 2, g: g * 2, b: b * 2, a: 255 };
  }

  return { r: 0, g: 0, b: 0, a: 255 };
}

should work, but needs testing (thanks @dimfeld )

[dimfeld]

And then as mentioned later in our conversation, when reading the channel values back, just & 0xFE each channel value before creating the Map key to do the lookup and you should be good.

Link to Brave Github issue for reference, which is 4 years old but still appears to work this way in my testing brave/brave-browser#9591 (comment)

[techniq]

Fixed in 1.0.13 and 2.0.0-next.44