Validate external protocols before launching on Windows

Bug: 889459
Change-Id: Id33ca6444bff1e6dd71b6000823cf6fec09746ef
Reviewed-on: https://chromium-review.googlesource.com/c/1256208
Reviewed-by: Greg Thompson <grt@chromium.org>
Commit-Queue: Mustafa Emre Acer <meacer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#597611}
void OnSettingsAppFinished(
    std::unique_ptr<DefaultBrowserActionRecorder> recorder,
    const base::Closure& on_finished_callback) {
  recorder.reset();
  on_finished_callback.Run();
}

void OnSettingsAppFinished(
    std::unique_ptr<DefaultBrowserActionRecorder> recorder,
    const base::Closure& on_finished_callback) {
  recorder.reset();
  on_finished_callback.Run();
}
