Fixes the cache lock issue.

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 94ac7b1e3e03dc6258aa53fd429f47c5983a1a15..bd55e28a04a9347a9198af8fc3049a4d0e39d2c3 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -111230,6 +111230,13 @@ value.
   <suffix name="SentRequest" label="The request was sent over the network."/>
   <suffix name="Used"
       label="A cache entry was used without using the network."/>
+  <suffix name="JoinSharedWriting"
+      label="The request joined shared writing with other requests."/>
+  <suffix name="InitiateSharedWriting"
+      label="The request initiated shared writing."/>
+  <suffix name="DoomSharedWriting"
+      label="The request doomed the shared writing entry, after validation
+             did not match over the network."/>
   <affected-histogram name="HttpCache.AccessToDone"/>
 </histogram_suffixes>
 
@@ -111242,6 +111249,17 @@ value.
       label="A cached resource existed and was updated over the network."/>
   <suffix name="Validated"
       label="A cached resource existed and was validated over the network."/>
+  <suffix name="JoinSharedWriting"
+      label="The request joined shared writing with other requests."/>
+  <suffix name="DoomSharedWriting"
+      label="The request doomed the shared writing entry, after validation
+             did not match over the network."/>
+  <suffix name="CantConditionalize.InitiateSharedWriting"
+      label="The request initiated shared writing."/>
+  <suffix name="NotCached.InitiateSharedWriting"
+      label="The request initiated shared writing."/>
+  <suffix name="Updated.InitiateSharedWriting"
+      label="The request initiated shared writing."/>
   <affected-histogram name="HttpCache.BeforeSend"/>
   <affected-histogram name="HttpCache.PercentBeforeSend"/>
 </histogram_suffixes>