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..5652eb05d8645f99589587eea57091fede25a813 100644
--- a/chrome/common/net/net_error_info.h
+++ b/chrome/common/net/net_error_info.h
@@ -7,6 +7,26 @@
 
 namespace chrome_common_net {
 
+// Network error page events.  Used for UMA statistics.
+enum NetworkErrorPageEvent {
+  NETWORK_ERROR_PAGE_SHOWN,                      // Error pages shown.
+
+  NETWORK_ERROR_PAGE_RELOAD_BUTTON_SHOWN,        // Reload buttons shown.
+  NETWORK_ERROR_PAGE_RELOAD_BUTTON_CLICKED,      // Reload button clicked.
+  NETWORK_ERROR_PAGE_RELOAD_BUTTON_ERROR,        // Reload button clicked
+                                                 // -> error.
+
+  NETWORK_ERROR_PAGE_LOAD_STALE_BUTTON_SHOWN,    // Load stale buttons shown.
+  NETWORK_ERROR_PAGE_LOAD_STALE_BUTTON_CLICKED,  // Load stale button clicked.
+  NETWORK_ERROR_PAGE_LOAD_STALE_BUTTON_ERROR,    // Load stale buttons -> error.
+
+  NETWORK_ERROR_PAGE_MORE_BUTTON_CLICKED,        // More button clicked.
+
+  NETWORK_ERROR_PAGE_BROWSER_INITIATED_RELOAD,   // Reload from browser.
+
+  NETWORK_ERROR_PAGE_EVENT_MAX,
+};
+
 // The status of a DNS probe that the NetErrorTabHelper may or may not have
 // started.
 //
@@ -62,6 +82,9 @@ 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[];