Service Worker: Split StartWorker metrics into new and installed versions.

This starts track down why the "StartWorker.Status" metric shows more
failures than expected.

We expect different characteristics for starting a new worker vs. one that
is already installed. It wouldn't be surprising for a new worker to fail
to start due to a syntax error or take a longer time due to downloading
the script, for example. Therefore, split the metrics to distinguish between
the two cases.

BUG=448003

Review URL: https://codereview.chromium.org/1085553002

Cr-Commit-Position: refs/heads/master@{#324993}

3 files changed, 52 insertions, 6 deletions

diff --git a/content/browser/service_worker/service_worker_metrics.cc b/content/browser/service_worker/service_worker_metrics.cc
index 5c10a67..69f0d85 100644
--- a/content/browser/service_worker/service_worker_metrics.cc
+++ b/content/browser/service_worker/service_worker_metrics.cc
@@ -4,7 +4,7 @@
 
 #include "content/browser/service_worker/service_worker_metrics.h"
 
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics_action.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
@@ -75,4 +75,24 @@ void ServiceWorkerMetrics::CountControlledPageLoad(const GURL& url) {
                           base::Bind(&RecordURLMetricOnUI, url));
 }
 
+void ServiceWorkerMetrics::RecordStartWorkerStatus(
+    ServiceWorkerStatusCode status,
+    bool is_installed) {
+  if (is_installed) {
+    UMA_HISTOGRAM_ENUMERATION("ServiceWorker.StartWorker.Status", status,
+                              SERVICE_WORKER_ERROR_MAX_VALUE);
+  } else {
+    UMA_HISTOGRAM_ENUMERATION("ServiceWorker.StartNewWorker.Status", status,
+                              SERVICE_WORKER_ERROR_MAX_VALUE);
+  }
+}
+
+void ServiceWorkerMetrics::RecordStartWorkerTime(const base::TimeDelta& time,
+                                                 bool is_installed) {
+  if (is_installed)
+    UMA_HISTOGRAM_MEDIUM_TIMES("ServiceWorker.StartWorker.Time", time);
+  else
+    UMA_HISTOGRAM_MEDIUM_TIMES("ServiceWorker.StartNewWorker.Time", time);
+}
+
 }  // namespace content
diff --git a/content/browser/service_worker/service_worker_metrics.h b/content/browser/service_worker/service_worker_metrics.h
index 8b05856..705deb7 100644
--- a/content/browser/service_worker/service_worker_metrics.h
+++ b/content/browser/service_worker/service_worker_metrics.h
@@ -52,6 +52,16 @@ class ServiceWorkerMetrics {
   // Counts the number of page loads controlled by a Service Worker.
   static void CountControlledPageLoad(const GURL& url);
 
+  // Records the result of trying to start a worker. |is_installed| indicates
+  // whether the version has been installed.
+  static void RecordStartWorkerStatus(ServiceWorkerStatusCode status,
+                                      bool is_installed);
+
+  // Records the time taken to successfully start a worker. |is_installed|
+  // indicates whether the version has been installed.
+  static void RecordStartWorkerTime(const base::TimeDelta& time,
+                                    bool is_installed);
+
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ServiceWorkerMetrics);
 };
diff --git a/content/browser/service_worker/service_worker_version.cc b/content/browser/service_worker/service_worker_version.cc
index 681e2b6..0c5202d 100644
--- a/content/browser/service_worker/service_worker_version.cc
+++ b/content/browser/service_worker/service_worker_version.cc
@@ -19,6 +19,7 @@
 #include "content/browser/service_worker/embedded_worker_registry.h"
 #include "content/browser/service_worker/service_worker_context_core.h"
 #include "content/browser/service_worker/service_worker_context_wrapper.h"
+#include "content/browser/service_worker/service_worker_metrics.h"
 #include "content/browser/service_worker/service_worker_registration.h"
 #include "content/browser/service_worker/service_worker_utils.h"
 #include "content/browser/storage_partition_impl.h"
@@ -343,6 +344,21 @@ void AddNonWindowClient(ServiceWorkerProviderHost* host,
   clients->push_back(client_info);
 }
 
+bool IsInstalled(ServiceWorkerVersion::Status status) {
+  switch (status) {
+    case ServiceWorkerVersion::NEW:
+    case ServiceWorkerVersion::INSTALLING:
+    case ServiceWorkerVersion::REDUNDANT:
+      return false;
+    case ServiceWorkerVersion::INSTALLED:
+    case ServiceWorkerVersion::ACTIVATING:
+    case ServiceWorkerVersion::ACTIVATED:
+      return true;
+  }
+  NOTREACHED() << "Unexpected status: " << status;
+  return false;
+}
+
 }  // namespace
 
 const int ServiceWorkerVersion::kStartWorkerTimeoutMinutes = 5;
@@ -1731,15 +1747,15 @@ void ServiceWorkerVersion::RecordStartWorkerResult(
 
   // Failing to start a doomed worker isn't interesting and very common when
   // update dooms because the script is byte-to-byte identical.
-  if (is_doomed_)
+  if (is_doomed_ || status_ == REDUNDANT)
     return;
 
-  UMA_HISTOGRAM_ENUMERATION("ServiceWorker.StartWorker.Status", status,
-                            SERVICE_WORKER_ERROR_MAX_VALUE);
+  ServiceWorkerMetrics::RecordStartWorkerStatus(status, IsInstalled(status_));
+
   if (status == SERVICE_WORKER_OK && !start_time.is_null() &&
       !skip_recording_startup_time_) {
-    UMA_HISTOGRAM_MEDIUM_TIMES("ServiceWorker.StartWorker.Time",
-                               GetTickDuration(start_time));
+    ServiceWorkerMetrics::RecordStartWorkerTime(GetTickDuration(start_time),
+                                                IsInstalled(status_));
   }
 
   if (status != SERVICE_WORKER_ERROR_TIMEOUT)