V8ValueConverter::ToV8Value should not trigger setters

BUG=606390

Review URL: https://codereview.chromium.org/1918793003

Cr-Commit-Position: refs/heads/master@{#390045}
bool V8ValueConverter::Strategy::FromV8Undefined(base::Value** out) const {
  return false;
}

bool V8ValueConverter::Strategy::FromV8Undefined(base::Value** out) const {
  return false;
}
