Surface button for loading stale cache copy on net error page.

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 {
 
+// Network error page events.  Used for UMA statistics.
+enum NetworkErrorPageEvent {
+  NET_ERROR_PAGE_SHOWN,                      // Error pages shown.

[sky, 2014/04/17 15:26:54]

I would prefer you followed the convention in content and didn't shorten these,
eg NETWORK_ERROR_...

[Randy Smith (Not in Mondays), 2014/04/17 16:04:54]

My 80 columns!!  :-}  Done.

+
+  NET_ERROR_PAGE_RELOAD_BUTTON_SHOWN,        // Reload buttons shown.
+  NET_ERROR_PAGE_RELOAD_BUTTON_CLICKED,      // Reload button clicked.
+  NET_ERROR_PAGE_RELOAD_BUTTON_ERROR,        // Reload button clicked -> error.
+
+  NET_ERROR_PAGE_LOAD_STALE_BUTTON_SHOWN,    // Load stale buttons shown.
+  NET_ERROR_PAGE_LOAD_STALE_BUTTON_CLICKED,  // Load stale button clicked.
+  NET_ERROR_PAGE_LOAD_STALE_BUTTON_ERROR,    // Load stale buttons -> error.
+
+  NET_ERROR_PAGE_MORE_BUTTON_CLICKED,        // More button clicked.
+
+  NET_ERROR_PAGE_BROWSER_INITIATED_RELOAD,   // Reload initiated from browser.
+
+  NET_ERROR_PAGE_EVENT_MAX,
+};
+
 // The status of a DNS probe that the NetErrorTabHelper may or may not have
 // started.
 //
 // The DNS_PROBE_FINISHED_* values are used in histograms, so:
 // 1. FINISHED_UNKNOWN must remain the first FINISHED_* value.
 // 2. FINISHED_* values must not be rearranged relative to FINISHED_UNKNOWN.
 // 3. New FINISHED_* values must be inserted at the end.
 // 4. New non-FINISHED_* values cannot be inserted.
 enum DnsProbeStatus {
   // A DNS probe may be run for this error page.  (This status is only used on
@@ skipping 35 matching lines @@
 // |status| is an int because error codes are ints by the time they get to the
 // localized error system, and we don't want to require the caller to cast back
 // to a probe status.  The function will NOTREACHED() and return an empty
 // string if given an int that does not match a value in DnsProbeStatus (or if
 // it is DNS_PROBE_MAX, which is not a real status).
 const char* DnsProbeStatusToString(int status);
 
 // Returns true if |status| is one of the DNS_PROBE_FINISHED_* statuses.
 bool DnsProbeStatusIsFinished(DnsProbeStatus status);
 
+// Record specific error page events.
+void RecordEvent(NetworkErrorPageEvent event);
+
 // The error domain used to pass DNS probe statuses to the localized error
 // code.
 extern const char kDnsProbeErrorDomain[];
 
 }  // namespace chrome_common_net
 
 #endif  // CHROME_COMMON_NET_NET_ERROR_INFO_H_