Get signals working in the EXTRA_DATA section of MHTML

chrome/browser/flag_descriptions.h

Index: chrome/browser/flag_descriptions.h
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index 9e97ec7c9d7d892dd9a82f229e86008569aca074..84c8e8f2af153dc4607642e8e3f8760a3970095c 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -2216,6 +2216,14 @@ extern const char kOfflinePagesSvelteConcurrentLoadingName[];
 // (512MB RAM) devices.
 extern const char kOfflinePagesSvelteConcurrentLoadingDescription[];
 
+// Name for the flag to enable collecting load timing signals to improve

[Dmitry Titov, 2017/03/31 18:05:53]

Unclear sentence... 

The signals will not only be time-based... Maybe "the flag to enable collecting
loading telemetry in MHTML snapshots"?

same below.

[Pete Williamson, 2017/03/31 21:58:04]

Changed "load timing" to "load completeness"

+// prerendering snapshot timing.
+extern const char kOfflinePagesLoadSignalCollectingName[];
+
+// Description for the flag to enable collecting load timing signals to improve
+// prerendering snapshot timing.
+extern const char kOfflinePagesLoadSignalCollectingDescription[];
+
 // Name for the flag to enable offline pages to be prefetched.
 extern const char kOfflinePagesPrefetchingName[];