Delegate PersistedLogs metrics recording

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 559eba304158188c8c51f02806df16622ecad5fe..46d92b9ecbe4d98c12667df746ed5c6688297d1c 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -48622,6 +48622,12 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>The amount of time that elapsed during CreateProfilePrefs.</summary>
 </histogram>
 
+<histogram name="PrefService.PersistentLogRecallProtobufs"
+    enum="PersistedLogsLogReadStatus">
+  <owner>holte@chromium.org</owner>
+  <summary>The status when loading PersistedLogs from Prefs.</summary>
+</histogram>
+
 <histogram name="PreloadScanner.Counts" units="preloads">
   <obsolete>
     Deprecated 5/25/2016 in favor of PreloadScanner.Counts2
@@ -98463,6 +98469,17 @@ value.
   <int value="11" label="PERMISSION_FLASH"/>
 </enum>
 
+<enum name="PersistedLogsLogReadStatus" type="int">
+  <int value="0" label="RECALL_SUCCESS"/>
+  <int value="1" label="LIST_EMPTY"/>
+  <int value="2" label="LIST_SIZE_MISSING"/>
+  <int value="3" label="LIST_SIZE_TOO_SMALL"/>
+  <int value="4" label="LIST_SIZE_CORRUPTION"/>

[rkaplow, 2016/12/19 21:44:33]

this isn't matching 
https://codesearch.chromium.org/chromium/src/components/metrics/persisted_log...,
missing a couple of entries.

[Steven Holte, 2016/12/19 21:53:12]

Good catch

+  <int value="5" label="CHECKSUM_CORRUPTION"/>
+  <int value="6" label="CHECKSUM_STRING_CORRUPTION"/>
+  <int value="7" label="DEPRECATED_XML_PROTO_MISMATCH"/>
+</enum>
+
 <enum name="PersistentHistogramsInitResult" type="int">
   <int value="0" label="Local-Memory Success"/>
   <int value="1" label="Local-Memory Failure"/>