Cert - protobufs to serialize and deserialize CertVerifierCache.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 18549fcffd7d645849e7c902df6b3c583b30daf6..1ebc816a71f2cf87accb72a4a990acdacb808769 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -25624,6 +25624,25 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Net.CertVerifierCachePersister.LoadCacheSize">
+  <owner>rtenneti@chromium.org</owner>
+  <summary>
+    The number of CertVerificationCache's entries that were deserialized.

[Ryan Sleevi, 2016/06/08 21:38:10]

GRAMMAR: This feels weird (notably, "CertVerificationCache's entries"). This
also feels like it all three might be at the wrong layer - the time spent (and
number of entries deserialized) seems not relevant as a whole, but to a specific
use (in this case, presumably, a profile's serialization/deserialization time)

Because there is no limit on how many CertVerificationCaches there are, nor as
to how many CachingCertVerifiers there are (and of course, there are many - per
profile, URLRequestContext, etc), then the metric you're collecting here is not
as valuable.

Moving this to be dealt with in your #5 case seems more relevant to what you're
trying to measure, since you're concerned about a very specific callsites' time
spent, right?

[ramant (doing other things), 2016/06/09 00:51:39]

Deleted this.

Done.

+  </summary>
+</histogram>
+
+<histogram name="Net.CertVerifierCachePersister.LoadCacheTime" units="ms">
+  <owner>rtenneti@chromium.org</owner>
+  <summary>
+    The amount of time spent deserializing and populating CertVerifiers' cache.

[Ryan Sleevi, 2016/06/08 21:38:10]

GRAMMAR: Either caches should be plural (to reflect the plurality of
CertVerifiers), or you should make CertVerifiers' singular - and "populating a
CertVerifier's cache."

Same with below

[ramant (doing other things), 2016/06/09 00:51:39]

Done.

+  </summary>
+</histogram>
+
+<histogram name="Net.CertVerifierCachePersister.SerializeTime" units="ms">
+  <owner>rtenneti@chromium.org</owner>
+  <summary>The amount of time spent serializing CertVerifiers' cache.</summary>
+</histogram>
+
 <histogram name="Net.CoalescePotential" enum="CoalescePotentialPackets">
   <obsolete>
     Deprecated 04/2016 as doesn't have data nor owner.