[Refactor] Rename DnsResolutionObserver --> HostResolver::Observer....

net/base/dns_resolution_observer.h

-// Copyright (c) 2006-2008 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.
-
-// This file supports network stack independent notification of progress
-// towards resolving a hostname.
-
-// The observer class supports exactly one active (Add'ed) instance, and in
-// typical usage, that observer will be Add'ed during process startup, and
-// Remove'd during process termination.
-
-
-#ifndef NET_BASE_DNS_RESOLUTION_OBSERVER_H_
-#define NET_BASE_DNS_RESOLUTION_OBSERVER_H_
-
-#include <string>
-
-#include "net/base/host_resolver.h"
-
-class GURL;
-
-namespace net {
-
-// TODO(eroman): Move this interface to HostResolver::Observer.
-class DnsResolutionObserver {
- public:
-  virtual ~DnsResolutionObserver() {}
-
-  // For each OnStartResolution() notification, there should be a later
-  // OnFinishResolutionWithStatus() indicating completion of the resolution
-  // activity.
-  // Related pairs of notification will arrive with matching id values.
-  // A caller may use the id values to match up these asynchronous calls
-  // from among a larger call stream.
-  virtual void OnStartResolution(int id,
-                                 const HostResolver::RequestInfo& info) = 0;
-  virtual void OnFinishResolutionWithStatus(
-      int id,
-      bool was_resolved,
-      const HostResolver::RequestInfo& info) = 0;
-};
-
-}  // namspace net
-
-#endif  // NET_BASE_DNS_RESOLUTION_OBSERVER_H_