service worker: Add UMA for retry count for storage service recovery

Bug: 1133143
Change-Id: I3f0f082402506138ce00e9228e58549fe8ca7db6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2532161
Commit-Queue: Mark Pearson <mpearson@chromium.org>
Auto-Submit: Kenichi Ishibashi <bashi@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Reviewed-by: Makoto Shimazu <shimazu@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827082}

content/browser/service_worker/service_worker_registry.cc

@@ -8,6 +8,7 @@
 
 #include "base/memory/ptr_util.h"
 #include "base/memory/weak_ptr.h"
+#include "base/metrics/histogram_functions.h"
 #include "base/stl_util.h"
 #include "base/task/post_task.h"
 #include "base/trace_event/trace_event.h"
@@ -85,6 +86,11 @@ void CompleteFindSoon(
                                     status, std::move(callback)));
 }
 
+void RecordRetryCount(size_t retries) {
+  base::UmaHistogramCounts100("ServiceWorker.Storage.RetryCountForRecovery",
+                              retries);
+}
+
 }  // namespace
 
 // A helper class that runs on the IO thread to observe storage policy updates.
@@ -1353,6 +1359,7 @@ void ServiceWorkerRegistry::OnRemoteStorageDisconnected() {
   if (connection_state_ == ConnectionState::kRecovering) {
     ++recovery_retry_counts_;
     if (recovery_retry_counts_ > kMaxRetryCounts) {
+      RecordRetryCount(kMaxRetryCounts);
       CHECK(false) << "The Storage Service consistently crashes.";
       return;
     }
@@ -1375,6 +1382,8 @@ void ServiceWorkerRegistry::OnRemoteStorageDisconnected() {
 void ServiceWorkerRegistry::DidRecover() {
   DCHECK_CURRENTLY_ON(ServiceWorkerContext::GetCoreThreadId());
 
+  RecordRetryCount(recovery_retry_counts_);
+
   recovery_retry_counts_ = 0;
   connection_state_ = ConnectionState::kNormal;
   // TODO(crbug.com/1133143): Retry mojo method calls which are invoked during

tools/metrics/histograms/histograms_xml/service/histograms.xml

@@ -1094,6 +1094,18 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   </summary>
 </histogram>
 
+<histogram name="ServiceWorker.Storage.RetryCountForRecovery" units="retries"
+    expires_after="2021-06-30">
+  <owner>bashi@chromium.org</owner>
+  <owner>chrome-worker@google.com</owner>
+  <summary>
+    The counts of retries to recover after a Storage Service crash. Logged after
+    a recovery, or the maximum number of retries is exceeded See
+    ServiceWorkerRegistry::OnRemoteStorageDisconnected() for the maximum number
+    of retries.
+  </summary>
+</histogram>
+
 <histogram name="ServiceWorker.WorkerForMessageFound" enum="Boolean"
     expires_after="M85">
   <owner>falken@chromium.org</owner>