Display DNS probe results.

chrome/common/net/net_error_info.h

 // Copyright (c) 2013 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_COMMON_NET_NET_ERROR_INFO_H_
 #define CHROME_COMMON_NET_NET_ERROR_INFO_H_
 
 namespace chrome_common_net {
 
-enum DnsProbeResult {
-  DNS_PROBE_UNKNOWN,
-  DNS_PROBE_NO_INTERNET,
-  DNS_PROBE_BAD_CONFIG,
-  DNS_PROBE_NXDOMAIN,
+// The status of a DNS probe that the NetErrorTabHelper may or may not have
+// started.
+enum DnsProbeStatus {
+  // A DNS probe may be run for this error page.  (This status is only used on
+  // the renderer side before it's received a status update from the browser.)
+  DNS_PROBE_POSSIBLE,

[mmenke, 2013/06/13 20:04:55]

I suggest merging this with DNS_PROBE_STARTED, and call it DNS_PROBE_PENDING or
DNS_PROBE_WAIT or somesuch, a bit like ERR_IO_PENDING.

A "last_state_" of DNS_PROBE_POSSIBLE, in particular, seems a little weird.

[Deprecated (see juliatuttle), 2013/06/18 19:36:37]

The two are potentially different; if we ever add a spinner, it will be shown
for DNS_PROBE_STARTED but not DNS_PROBE_POSSIBLE.  The idea is that
DNS_PROBE_POSSIBLE should show the common error page elements, but not start a
spinner or anything that would flicker annoyingly if we immediately go to
DNS_PROBE_NOT_RUN.

+
+  // A DNS probe will not be run for this error page.  (This happens if the
+  // user has the "Use web service to resolve navigation errors" preference
+  // turned off, or if probes are disabled by the field trial.)
+  DNS_PROBE_NOT_RUN,
+
+  // A DNS probe has been started for this error page.  The renderer should
+  // expect to receive another IPC with one of the FINISHED statuses once the
+  // probe has finished (as long as the error page is still loaded).
+  DNS_PROBE_STARTED,
+
+  // A DNS probe has finished with one of the following results:
+
+  // The probe was inconclusive..
+  DNS_PROBE_FINISHED_UNKNOWN,
+
+  // There's no internet connection.
+  DNS_PROBE_FINISHED_NO_INTERNET,
+
+  // The DNS configuration is wrong, or the servers are down or broken.
+  DNS_PROBE_FINISHED_BAD_CONFIG,
+
+  // The DNS servers are working fine, so the domain must not exist.
+  DNS_PROBE_FINISHED_NXDOMAIN,
+
   DNS_PROBE_MAX
 };
 
+const char* DnsProbeStatusToString(int status);
+bool DnsProbeStatusIsFinished(DnsProbeStatus status);
+
+bool DnsProbesEnabledByFieldTrial();
+
+extern const char kDnsProbeErrorDomain[];
+
 }  // namespace chrome_common_net
 
 #endif  // CHROME_COMMON_NET_NET_ERROR_INFO_H_