ServiceWorker: Add UMA for storage recovery operation

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 4ee573300b621c9be554f6874631025cfacb118f..5eb82748e26a0e0ca5e250d196a1647ca0d0e3cd 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -33780,6 +33780,14 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <summary>Execution time of ServiceWorkerGlobalScope.onactivate.</summary>
 </histogram>
 
+<histogram name="ServiceWorker.Database.DestroyDatabaseResult"
+    enum="ServiceWorkerDatabaseStatus">
+  <owner>nhiroki@chromium.org</owner>
+  <summary>
+    Records result of destroy database operations in ServiceWorkerDatabase.
+  </summary>
+</histogram>
+
 <histogram name="ServiceWorker.Database.OpenResult"
     enum="ServiceWorkerDatabaseStatus">
   <owner>nhiroki@chromium.org</owner>
@@ -33894,6 +33902,14 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="ServiceWorker.Storage.DeleteAndStartOverResult"
+    enum="ServiceWorkerDeleteAndStartOverResult">
+  <owner>nhiroki@chromium.org</owner>
+  <summary>
+    Records result of storage recovery operations in ServiceWorkerStorage.
+  </summary>
+</histogram>
+
 <histogram name="ServiceWorkerCache.Cache" units="milliseconds">
   <owner>dmurph@chromium.org</owner>
   <summary>
@@ -59089,6 +59105,12 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="4" label="Operation Error"/>
 </enum>
 
+<enum name="ServiceWorkerDeleteAndStartOverResult" type="int">
+  <int value="0" label="OK"/>
+  <int value="1" label="Failed to delete ServiceWorkerDatabase"/>
+  <int value="2" label="Failed to delete ServiceWorkerDiskCache"/>
+</enum>
+
 <enum name="ServiceWorkerReadResponseResult" type="int">
   <int value="0" label="OK"/>
   <int value="1" label="Read headers error"/>