input::placeholder selector breaks display in Chrome 55

[n1313]

Some elements of UI are looking weird in Chrome 55 (Windows) because of this input::placeholder selector. It should either be vendor-prefixed or separated from the rest.

[sapegin]

The problem is that it breaks jss-isolate, because that unsupported in Chrome 55 pseudo element discards the whole jss-isolate selector:

… .input-0-68, .input-0-68::placeholder, .list-0-71 … {}

So we need to disable isolation for rules with ``:

'&::placeholder': {
  isolate: false
  // ...
}