Update WebAPK after the user closes WebAPK

tools/metrics/histograms/enums.xml

Index: tools/metrics/histograms/enums.xml
diff --git a/tools/metrics/histograms/enums.xml b/tools/metrics/histograms/enums.xml
index a6eb706a00fd608de2a87924de02012f92d4549a..17bd94bb998ce7f2a5e0ed2dafda3161ea55e165 100644
--- a/tools/metrics/histograms/enums.xml
+++ b/tools/metrics/histograms/enums.xml
@@ -2462,6 +2462,10 @@ uploading your change for review.  These are checked by presubmit scripts.
   <int value="5" label="Chrome minidump uploading task"/>
   <int value="6" label="Offlining pages task"/>
   <int value="7" label="Offline page prefetch task"/>
+  <int value="8" label="Download service task"/>
+  <int value="9" label="Download cleanup task"/>
+  <int value="10" label="WebView variations seed fetch task"/>
+  <int value="11" label="WebAPK update task"/>
 </enum>
 
 <enum name="BackgroundTracingState">
@@ -39848,9 +39852,10 @@ Called by update_traffic_annotation_histograms.py.-->
 </enum>
 
 <enum name="WebApkUpdateRequestSent">
-  <int value="0" label="Sent immediately after an update check"/>
-  <int value="1" label="Sent when WebAPK is moved to background"/>
-  <int value="2" label="Sent by forcing an update"/>
+  <int value="0" label="Sent immediately after an update check (deprecated)"/>
+  <int value="1" label="Sent when WebAPK is moved to background (deprecated)"/>
+  <int value="2" label="Sent by forcing an update (deprecated)"/>
+  <int value="3" label="Sent when WebAPK is closed"/>
 </enum>
 
 <enum name="WebApkUserAction">