Remove unused HostResolver::Observer.

net/base/test_host_resolver_observer.h

-// Copyright (c) 2011 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 NET_BASE_TEST_HOST_RESOLVER_OBSERVER_H_
-#define NET_BASE_TEST_HOST_RESOLVER_OBSERVER_H_
-#pragma once
-
-#include "net/base/host_resolver.h"
-
-#include <vector>
-
-namespace net {
-
-bool operator==(const HostResolver::RequestInfo& a,
-                const HostResolver::RequestInfo& b);
-
-// Observer that just makes note of how it was called. The test code can then
-// inspect to make sure it was called with the right parameters.  Used by
-// HostResolverImpl and AsyncHostResolver unit tests.
-class TestHostResolverObserver : public HostResolver::Observer {
- public:
-  TestHostResolverObserver();
-  virtual ~TestHostResolverObserver();
-
-  // HostResolver::Observer methods:
-  virtual void OnStartResolution(int id, const HostResolver::RequestInfo& info);
-  virtual void OnFinishResolutionWithStatus(
-      int id,
-      bool was_resolved,
-      const HostResolver::RequestInfo& info);
-  virtual void OnCancelResolution(
-      int id,
-      const HostResolver::RequestInfo& info);
-
-  // Tuple (id, info).
-  struct StartOrCancelEntry {
-    StartOrCancelEntry(int id, const HostResolver::RequestInfo& info)
-        : id(id), info(info) {}
-
-    bool operator==(const StartOrCancelEntry& other) const {
-      return id == other.id && info == other.info;
-    }
-
-    int id;
-    HostResolver::RequestInfo info;
-  };
-
-  // Tuple (id, was_resolved, info).
-  struct FinishEntry {
-    FinishEntry(int id, bool was_resolved,
-                const HostResolver::RequestInfo& info)
-        : id(id), was_resolved(was_resolved), info(info) {}
-
-    bool operator==(const FinishEntry& other) const {
-      return id == other.id &&
-             was_resolved == other.was_resolved &&
-             info == other.info;
-    }
-
-    int id;
-    bool was_resolved;
-    HostResolver::RequestInfo info;
-  };
-
-  std::vector<StartOrCancelEntry> start_log;
-  std::vector<FinishEntry> finish_log;
-  std::vector<StartOrCancelEntry> cancel_log;
-};
-
-}  // namespace net
-
-#endif  // NET_BASE_TEST_HOST_RESOLVER_OBSERVER_H_