Revert 211950 "Display DNS probe results."

chrome/browser/net/dns_probe_service.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 CHROME_BROWSER_NET_DNS_PROBE_SERVICE_H_
 #define CHROME_BROWSER_NET_DNS_PROBE_SERVICE_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
-#include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
-#include "chrome/browser/net/dns_probe_runner.h"
+#include "chrome/browser/net/dns_probe_job.h"
 #include "chrome/common/net/net_error_info.h"
 #include "net/base/network_change_notifier.h"
 
 namespace net {
-class DnsClient;
 struct DnsConfig;
 }
 
 namespace chrome_browser_net {
 
-// Probes the system and public DNS servers to determine the (probable) cause
-// of a recent DNS-related page load error.  Coalesces multiple probe requests
-// (perhaps from multiple tabs) and caches the results.
-//
-// Uses a single DNS attempt per config, and doesn't randomize source ports.
-class DnsProbeService : public net::NetworkChangeNotifier::DNSObserver {
+class DnsProbeService : public net::NetworkChangeNotifier::IPAddressObserver {
  public:
-  typedef base::Callback<void(chrome_common_net::DnsProbeStatus result)>
-      ProbeCallback;
+  typedef base::Callback<void(chrome_common_net::DnsProbeResult result)>
+      CallbackType;
 
   DnsProbeService();
   virtual ~DnsProbeService();
 
-  virtual void ProbeDns(const ProbeCallback& callback);
+  void ProbeDns(const CallbackType& callback);
 
-  // NetworkChangeNotifier::DNSObserver implementation:
-  virtual void OnDNSChanged() OVERRIDE;
+  // NetworkChangeNotifier::IPAddressObserver implementation:
+  virtual void OnIPAddressChanged() OVERRIDE;
 
-  void SetSystemClientForTesting(scoped_ptr<net::DnsClient> system_client);
-  void SetPublicClientForTesting(scoped_ptr<net::DnsClient> public_client);
-  void ClearCachedResultForTesting();
+ protected:
+  // This can be called by tests to pretend the cached reuslt has expired.
+  void ExpireResults();
 
  private:
   enum State {
-    STATE_NO_RESULT,
+    STATE_NO_RESULTS,
     STATE_PROBE_RUNNING,
-    STATE_RESULT_CACHED,
+    STATE_RESULTS_CACHED,
   };
 
-  void SetSystemClientToCurrentConfig();
-  void SetPublicClientToGooglePublicDns();
+  void StartProbes();
+  void OnProbesComplete();
+  void CallCallbacks();
 
-  // Starts a probe (runs system and public probes).
-  void StartProbes();
-  void OnProbeComplete();
-  // Calls all |pending_callbacks_| with the |cached_result_|.
-  void CallCallbacks();
-  // Clears a cached probe result.
-  void ClearCachedResult();
+  void OnProbeJobComplete(DnsProbeJob* job, DnsProbeJob::Result result);
+  chrome_common_net::DnsProbeResult EvaluateResults() const;
+  void HistogramProbes() const;
 
-  bool CachedResultIsExpired() const;
+  // These are expected to be overridden by tests to return mock jobs.
+  virtual scoped_ptr<DnsProbeJob> CreateSystemProbeJob(
+      const DnsProbeJob::CallbackType& job_callback);
+  virtual scoped_ptr<DnsProbeJob> CreatePublicProbeJob(
+      const DnsProbeJob::CallbackType& job_callback);
 
+  scoped_ptr<DnsProbeJob> CreateProbeJob(
+      const net::DnsConfig& dns_config,
+      const DnsProbeJob::CallbackType& job_callback);
+  void GetSystemDnsConfig(net::DnsConfig* config);
+  void GetPublicDnsConfig(net::DnsConfig* config);
+  bool ResultsExpired();
+
+  scoped_ptr<DnsProbeJob> system_job_;
+  scoped_ptr<DnsProbeJob> public_job_;
+  DnsProbeJob::Result system_result_;
+  DnsProbeJob::Result public_result_;
+  std::vector<CallbackType> callbacks_;
   State state_;
-  std::vector<ProbeCallback> pending_callbacks_;
+  chrome_common_net::DnsProbeResult result_;
   base::Time probe_start_time_;
-  chrome_common_net::DnsProbeStatus cached_result_;
-
-  // DnsProbeRunners for the system DNS configuration and a public DNS server.
-  DnsProbeRunner system_runner_;
-  DnsProbeRunner public_runner_;
+  // How many DNS request attempts the probe jobs will make before giving up
+  // (Overrides the attempts field in the system DnsConfig.)
+  const int dns_attempts_;
+  // How many nameservers the system config has.
+  int system_nameserver_count_;
+  // Whether the only system nameserver is 127.0.0.1.
+  bool system_is_localhost_;
 
   DISALLOW_COPY_AND_ASSIGN(DnsProbeService);
 };
 
 }  // namespace chrome_browser_net
 
 #endif  // CHROME_BROWSER_NET_DNS_PROBE_SERVICE_H_