Revert 85646 - Adds support for the DHCP portion of the WPAD (proxy auto-discovery) protocol.

net/proxy/dhcp_proxy_script_fetcher_win.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_PROXY_DHCP_PROXY_SCRIPT_FETCHER_WIN_H_
-#define NET_PROXY_DHCP_PROXY_SCRIPT_FETCHER_WIN_H_
-#pragma once
-
-#include <set>
-#include <string>
-
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/scoped_vector.h"
-#include "base/threading/non_thread_safe.h"
-#include "base/timer.h"
-#include "net/proxy/dhcp_proxy_script_fetcher.h"
-
-namespace net {
-
-class DhcpProxyScriptAdapterFetcher;
-class URLRequestContext;
-
-// Windows-specific implementation.
-class DhcpProxyScriptFetcherWin
-    : public DhcpProxyScriptFetcher,
-      public base::NonThreadSafe {
- public:
-  // Creates a DhcpProxyScriptFetcherWin that issues requests through
-  // |url_request_context|. |url_request_context| must remain valid for
-  // the lifetime of DhcpProxyScriptFetcherWin.
-  explicit DhcpProxyScriptFetcherWin(URLRequestContext* url_request_context);
-  virtual ~DhcpProxyScriptFetcherWin();
-
-  // DhcpProxyScriptFetcher implementation.
-  int Fetch(string16* utf16_text, CompletionCallback* callback) OVERRIDE;
-  void Cancel() OVERRIDE;
-  const GURL& GetPacURL() const OVERRIDE;
-  std::string GetFetcherName() const OVERRIDE;
-
-  // Sets |adapter_names| to contain the name of each network adapter on
-  // this machine that has DHCP enabled and is not a loop-back adapter. Returns
-  // false on error.
-  static bool GetCandidateAdapterNames(std::set<std::string>* adapter_names);
-
- protected:
-  // Event/state transition handlers
-  void OnFetcherDone(int result);
-  void OnWaitTimer();
-  void TransitionToDone();
-
-  // Virtual methods introduced to allow unit testing.
-  virtual DhcpProxyScriptAdapterFetcher* ImplCreateAdapterFetcher();
-  virtual bool ImplGetCandidateAdapterNames(
-      std::set<std::string>* adapter_names);
-  virtual int ImplGetMaxWaitMs();
-
-  // This is the outer state machine for fetching PAC configuration from
-  // DHCP.  It relies for sub-states on the state machine of the
-  // DhcpProxyScriptAdapterFetcher class.
-  //
-  // The goal of the implementation is to the following work in parallel
-  // for all network adapters that are using DHCP:
-  // a) Try to get the PAC URL configured in DHCP;
-  // b) If one is configured, try to fetch the PAC URL.
-  // c) Once this is done for all adapters, or a timeout has passed after
-  //    it has completed for the fastest adapter, return the PAC file
-  //    available for the most preferred network adapter, if any.
-  //
-  // The state machine goes from START->NO_RESULTS when it creates
-  // and starts an DhcpProxyScriptAdapterFetcher for each adapter.  It goes
-  // from NO_RESULTS->SOME_RESULTS when it gets the first result; at this
-  // point a wait timer is started.  It goes from SOME_RESULTS->DONE in
-  // two cases: All results are known, or the wait timer expired.  A call
-  // to Cancel() will also go straight to DONE from any state.  Any
-  // way the DONE state is entered, we will at that point cancel any
-  // outstanding work and return the best known PAC script or the empty
-  // string.
-  //
-  // The state machine is reset for each Fetch(), a call to which is
-  // only valid in states START and DONE, as only one Fetch() is
-  // allowed to be outstanding at any given time.
-  enum State {
-    STATE_START,
-    STATE_NO_RESULTS,
-    STATE_SOME_RESULTS,
-    STATE_DONE,
-  };
-
-  // Current state of this state machine.
-  State state_;
-
-  // Vector, in Windows' network adapter preference order, of
-  // DhcpProxyScriptAdapterFetcher objects that are or were attempting
-  // to fetch a PAC file based on DHCP configuration.
-  typedef ScopedVector<DhcpProxyScriptAdapterFetcher> FetcherVector;
-  FetcherVector fetchers_;
-
-  // Callback invoked when any fetcher completes.
-  CompletionCallbackImpl<DhcpProxyScriptFetcherWin> fetcher_callback_;
-
-  // Number of fetchers we are waiting for.
-  int num_pending_fetchers_;
-
-  // Lets our client know we're done. Not valid in states START or DONE.
-  CompletionCallback* client_callback_;
-
-  // Pointer to string we will write results to. Not valid in states
-  // START and DONE.
-  string16* destination_string_;
-
-  // PAC URL retrieved from DHCP, if any. Valid only in state STATE_DONE.
-  GURL pac_url_;
-
-  base::OneShotTimer<DhcpProxyScriptFetcherWin> wait_timer_;
-
-  scoped_refptr<URLRequestContext> url_request_context_;
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(DhcpProxyScriptFetcherWin);
-};
-
-}  // namespace net
-
-#endif  // NET_PROXY_DHCP_PROXY_SCRIPT_FETCHER_WIN_H_