Add a Dns preresolve interface in //content

content/browser/loader/resource_hints_controller.h

+// 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.
+
+#ifndef CONTENT_BROWSER_LOADER_RESOURCE_HINTS_CONTROLLER_H_
+#define CONTENT_BROWSER_LOADER_RESOURCE_HINTS_CONTROLLER_H_
+
+#include "base/macros.h"
+#include "net/base/completion_callback.h"
+#include "url/gurl.h"
+
+namespace content {
+
+class ResourceContext;
+
+// Scoped to the ResourceDispatcherHostImpl. This class manages DNS
+// preresolutions. Once resource hints go through mojo it will also respond to
+// mojo requests from Blink to preconnect / preresolve.
+class ResourceHintsController {
+ public:
+  ResourceHintsController();
+  ~ResourceHintsController();
+  int PreresolveUrl(content::ResourceContext* resource_context,
+                    const GURL& url,
+                    const net::CompletionCallback& callback);
+
+ private:
+  struct DnsRequest;
+  static void OnResolveComplete(std::unique_ptr<DnsRequest> request,
+                                const net::CompletionCallback& callback,
+                                int result);

[kinuko, 2016/05/25 02:07:04]

It looks both DnsRequest and OnResolveComplete can simply be a local struct /
method in an anon space in .cc?

...and at this point I feel we might not even need this Controller class at all?

[Charlie Harrison, 2016/05/25 12:20:14]

Yupp, I removed the class in the latest CL revision.

+
+  DISALLOW_COPY_AND_ASSIGN(ResourceHintsController);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_LOADER_RESOURCE_HINTS_CONTROLLER_H_