Display DNS probe results.

chrome/browser/net/net_error_tab_helper.h

Index: chrome/browser/net/net_error_tab_helper.h
diff --git a/chrome/browser/net/net_error_tab_helper.h b/chrome/browser/net/net_error_tab_helper.h
index e48fa9fe80835ba087600d8dcc00e9975b9998f5..5a5b9283fc2da54cfdfacf6d3aa3d732545c6ade 100644
--- a/chrome/browser/net/net_error_tab_helper.h
+++ b/chrome/browser/net/net_error_tab_helper.h
@@ -11,7 +11,6 @@
 #include "base/prefs/pref_member.h"
 #include "chrome/browser/net/dns_probe_service.h"
 #include "chrome/common/net/net_error_info.h"
-#include "chrome/common/net/net_error_tracker.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 
@@ -59,43 +58,39 @@ class NetErrorTabHelper
       const string16& error_description,
       content::RenderViewHost* render_view_host) OVERRIDE;
 
-  virtual void DidFinishLoad(
-      int64 frame_id,
-      const GURL& validated_url,
-      bool is_main_frame,
-      content::RenderViewHost* render_view_host) OVERRIDE;
-
- private:
-  friend class content::WebContentsUserData<NetErrorTabHelper>;
-
-  enum DnsProbeState {
-    DNS_PROBE_NONE,
-    DNS_PROBE_STARTED,
-    DNS_PROBE_FINISHED
-  };
-
+ protected:
   // |contents| is the WebContents of the tab this NetErrorTabHelper is
   // attached to.
   explicit NetErrorTabHelper(content::WebContents* contents);
+  virtual void StartDnsProbe();
+  virtual void SendInfo();
+  void OnDnsProbeFinished(chrome_common_net::DnsProbeStatus result);
 
-  void TrackerCallback(NetErrorTracker::DnsErrorPageState state);
-  void MaybePostStartDnsProbeTask();
-  void OnDnsProbeFinished(chrome_common_net::DnsProbeResult result);
-  void MaybeSendInfo();
+  // The status of a DNS probe that may or may not have started or finished.
+  // Since the renderer can change out from under the helper (in cross-process
+  // navigations), it re-sends the status whenever an error page commits.
+  chrome_common_net::DnsProbeStatus dns_probe_status_;
+
+ private:
+  friend class content::WebContentsUserData<NetErrorTabHelper>;
+
+  void OnMainFrameDnsError();
 
   void InitializePref(content::WebContents* contents);
   bool ProbesAllowed() const;
 
   base::WeakPtrFactory<NetErrorTabHelper> weak_factory_;
 
-  NetErrorTracker tracker_;
-  NetErrorTracker::DnsErrorPageState dns_error_page_state_;
+  // True if the last provisional load that started was for an error page.
+  bool is_error_page_;
 
-  DnsProbeState dns_probe_state_;
-  chrome_common_net::DnsProbeResult dns_probe_result_;
+  // True if the helper has seen a main frame page load fail with a DNS error,
+  // but has not yet seen a new page load successfully afterwards.
+  bool dns_error_active_;
 
   // Whether we are enabled to run by the DnsProbe-Enable field trial.
   const bool enabled_by_trial_;
+
   // "Use a web service to resolve navigation errors" preference is required
   // to allow probes.
   BooleanPrefMember resolve_errors_with_web_service_;