Make SDCH dictionaries persistent across browser restart.

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 d3ed17e789fadaa40776ec4251902eae07f96d6d..a193c3cfcee7f5e6edd22fa0782e95a3555d32cc 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -32051,6 +32051,13 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Sdch3.PersistenceDrop" enum="SdchPersistenceDrop">
+  <owner>rdsmith@chromium.org</owner>
+  <summary>
+    Tracks failures that occur when reading in persisted dictionary information.
+  </summary>
+</histogram>
+
 <histogram name="Sdch3.ProblemCodes_3" enum="SdchProblemCode">
   <obsolete>
     Deprecated 2014-11. Sdch3.ProblemCodes_5 used instead.
@@ -56139,10 +56146,21 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="2" label="FETCH_FAILED"/>
   <int value="3" label="FETCH_IGNORED_NO_SPACE"/>
   <int value="4" label="FETCH_MANAGER_REFUSED"/>
-  <int value="5" label="ADDED"/>
+  <int value="5" label="ADD_RESPONSE_TRIGGERRED"/>
   <int value="6" label="EVICT_FOR_DICT"/>
   <int value="7" label="EVICT_FOR_MEMORY"/>
   <int value="8" label="EVICT_FOR_DESTRUCTION"/>
+  <int value="9" label="ADD_PERSISTENCE_TRIGGERRED"/>
+</enum>
+
+<enum name="SdchPersistenceDrop" type="int">
+  <summary>
+    Errors that can occur when reading in persisted dictionary information. See
+    enum PersistenceDrop in net/sdch/sdch_owner.cc for more information.
+  </summary>
+  <int value="1" label="CREATION"/>
+  <int value="2" label="READ"/>
+  <int value="3" label="WRITE"/>
 </enum>
 
 <enum name="SdchProblemCode" type="int">