net: move host_resolver files from net/base to net/dns

net/base/host_resolver_proc.h

-// Copyright (c) 2012 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_HOST_RESOLVER_PROC_H_
-#define NET_BASE_HOST_RESOLVER_PROC_H_
-
-#include <string>
-
-#include "base/memory/ref_counted.h"
-#include "net/base/address_family.h"
-#include "net/base/net_export.h"
-
-namespace net {
-
-class AddressList;
-
-// Interface for a getaddrinfo()-like procedure. This is used by unit-tests
-// to control the underlying resolutions in HostResolverImpl. HostResolverProcs
-// can be chained together; they fallback to the next procedure in the chain
-// by calling ResolveUsingPrevious().
-//
-// Note that implementations of HostResolverProc *MUST BE THREADSAFE*, since
-// the HostResolver implementation using them can be multi-threaded.
-class NET_EXPORT HostResolverProc
-    : public base::RefCountedThreadSafe<HostResolverProc> {
- public:
-  explicit HostResolverProc(HostResolverProc* previous);
-
-  // Resolves |host| to an address list, restricting the results to addresses
-  // in |address_family|. If successful returns OK and fills |addrlist| with
-  // a list of socket addresses. Otherwise returns a network error code, and
-  // fills |os_error| with a more specific error if it was non-NULL.
-  virtual int Resolve(const std::string& host,
-                      AddressFamily address_family,
-                      HostResolverFlags host_resolver_flags,
-                      AddressList* addrlist,
-                      int* os_error) = 0;
-
- protected:
-  friend class base::RefCountedThreadSafe<HostResolverProc>;
-
-  virtual ~HostResolverProc();
-
-  // Asks the fallback procedure (if set) to do the resolve.
-  int ResolveUsingPrevious(const std::string& host,
-                           AddressFamily address_family,
-                           HostResolverFlags host_resolver_flags,
-                           AddressList* addrlist,
-                           int* os_error);
-
- private:
-  friend class HostResolverImpl;
-  friend class MockHostResolverBase;
-  friend class ScopedDefaultHostResolverProc;
-
-  // Sets the previous procedure in the chain.  Aborts if this would result in a
-  // cycle.
-  void SetPreviousProc(HostResolverProc* proc);
-
-  // Sets the last procedure in the chain, i.e. appends |proc| to the end of the
-  // current chain.  Aborts if this would result in a cycle.
-  void SetLastProc(HostResolverProc* proc);
-
-  // Returns the last procedure in the chain starting at |proc|.  Will return
-  // NULL iff |proc| is NULL.
-  static HostResolverProc* GetLastProc(HostResolverProc* proc);
-
-  // Sets the default host resolver procedure that is used by HostResolverImpl.
-  // This can be used through ScopedDefaultHostResolverProc to set a catch-all
-  // DNS block in unit-tests (individual tests should use MockHostResolver to
-  // prevent hitting the network).
-  static HostResolverProc* SetDefault(HostResolverProc* proc);
-  static HostResolverProc* GetDefault();
-
-  scoped_refptr<HostResolverProc> previous_proc_;
-  static HostResolverProc* default_proc_;
-
-  DISALLOW_COPY_AND_ASSIGN(HostResolverProc);
-};
-
-// Resolves |host| to an address list, using the system's default host resolver.
-// (i.e. this calls out to getaddrinfo()). If successful returns OK and fills
-// |addrlist| with a list of socket addresses. Otherwise returns a
-// network error code, and fills |os_error| with a more specific error if it
-// was non-NULL.
-NET_EXPORT_PRIVATE int SystemHostResolverProc(
-    const std::string& host,
-    AddressFamily address_family,
-    HostResolverFlags host_resolver_flags,
-    AddressList* addrlist,
-    int* os_error);
-
-}  // namespace net
-
-#endif  // NET_BASE_HOST_RESOLVER_PROC_H_