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

chrome/common/net/net_error_info.h

Index: chrome/common/net/net_error_info.h
diff --git a/chrome/common/net/net_error_info.h b/chrome/common/net/net_error_info.h
index 1f69f7cd36212e3d34563100c091ae3f2b3f3b42..a69823329f260a160b9f5b2849a7a61f4ee4e6a2 100644
--- a/chrome/common/net/net_error_info.h
+++ b/chrome/common/net/net_error_info.h
@@ -7,6 +7,25 @@
 
 namespace chrome_common_net {
 
+// Network error page events.  Used for UMA statistics.
+enum NetworkErrorPageEvent {
+  PAGE_SHOWN_EVENT,                // Error pages shown.
+
+  RELOAD_BUTTON_SHOWN_EVENT,       // Reload buttons shown.
+  RELOAD_BUTTON_CLICKED_EVENT,     // Reload button clicks.
+  RELOAD_BUTTON_ERROR_EVENT,       // Reload button clicks -> error.
+
+  LOAD_STALE_BUTTON_SHOWN_EVENT,   // Load stale buttons shown.
+  LOAD_STALE_BUTTON_CLICKED_EVENT, // Load stale button clicks.
+  LOAD_STALE_BUTTON_ERROR_EVENT,   // Load stale buttons -> error.
+
+  MORE_BUTTON_CLICKED_EVENT,       // More button clicks.
+
+  BROWSER_RELOAD_BUTTON_CLICKED_EVENT,    // Browser reload button clicks.
+
+  MAX_EVENT,
+};
+
 // The status of a DNS probe that the NetErrorTabHelper may or may not have
 // started.
 //
@@ -62,6 +81,9 @@ 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[];