Revert of Convert network hints to Mojo

components/network_hints/public/interfaces/network_hints.mojom

-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-module network_hints.mojom;
-
-import "url/mojo/url.mojom";
-
-[Native]
-struct LookupRequest;
-
-// These are messages sent from the renderer process to the browser process.
-interface NetworkHints {
-  // Request for a DNS prefetch of the names in the array.
-  DNSPrefetch(LookupRequest request);
-
-  // Request for preconnect to host providing resource specified by URL.
-  Preconnect(
-      url.mojom.Url url,       // preconnect target url
-      bool allow_credentials,  // Does connection have its credentials flag set
-      int32 count);            // number of connections
-};