Using std::move in chrome/browser/net.

Replace bellow codes with std::move in chrome/browser/net
      const base::Closure callback = callback_;
      callback_.Reset();
      callback.Run();

BUG=807724

Change-Id: I008cf9af9785272ddceb18fff4feba13e62fdac8
Reviewed-on: https://chromium-review.googlesource.com/1134715
Commit-Queue: Matt Menke <mmenke@chromium.org>
Reviewed-by: Matt Menke <mmenke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576099}

chrome/browser/net/dns_probe_runner.cc

@@ -137,9 +137,7 @@ void DnsProbeRunner::CallCallback() {
   DCHECK(!transaction_.get());
 
   // Clear callback in case it starts a new probe immediately.
-  const base::Closure callback = callback_;
-  callback_.Reset();
-  callback.Run();
+  std::move(callback_).Run();
 }
 
 }  // namespace chrome_browser_net