Update ServiceWorker event handled status histogram

content/browser/service_worker/service_worker_metrics.cc

Index: content/browser/service_worker/service_worker_metrics.cc
diff --git a/content/browser/service_worker/service_worker_metrics.cc b/content/browser/service_worker/service_worker_metrics.cc
index 00c51f8e554d4d9e48c820c9ba45d4353baa1559..aa6ea13548c42d47969d3fd3e23c51873b98021e 100644
--- a/content/browser/service_worker/service_worker_metrics.cc
+++ b/content/browser/service_worker/service_worker_metrics.cc
@@ -6,6 +6,7 @@
 
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics_action.h"
+#include "base/strings/string_util.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/user_metrics.h"
@@ -21,6 +22,30 @@ void RecordURLMetricOnUI(const GURL& url) {
       "ServiceWorker.ControlledPageUrl", url);
 }
 
+// Exclude NTP scope from UMA for now.
+// TOOD(kinuko): This should be temporary, revisit this once we have
+// better idea about what should be excluded in the UMA.
+// (UIThreadSearchTermsData::GoogleBaseURLValue() returns the google base
+// URL, but not available in content layer)
+bool IsGoogleLikeScope(const GURL& scope) {
+  const char google_like_scope_prefix[] = "https://www.google.";
+  return base::StartsWithASCII(scope.spec(), google_like_scope_prefix,
+                               false /* case sensitive */);

[falken, 2015/06/25 09:31:39]

StartsWithASCII with the bool param is now deprecated:
https://codereview.chromium.org/1182453004/

[kinuko, 2015/07/02 14:27:26]

Done.

+}
+
+enum EventHandledStatus {
+  EVENT_HANDLED,
+  EVENT_NOT_HANDLED,
+  EVENT_HANDLED_STATUS_MAX,

[falken, 2015/06/25 09:31:39]

nit: I slightly prefer NUM_TYPES over MAX. Some other enums use LAST, and then
pass "LAST + 1" to the histogram macro whereas we want to pass "MAX"
(CACHE_STORAGE_ERROR_LAST is an example). MAX and LAST seem easier to confuse
than NUM_TYPES.

[kinuko, 2015/07/02 14:27:26]

Done.

+};
+
+enum PerWorkerEventHandledStatus {
+  NO_EVENTS_HANDLED,
+  SOME_EVENTS_HANDLED,
+  ALL_EVENTS_HANDLED,
+  PER_WORKER_EVENT_HANDLED_STATUS_MAX,
+};
+
 }  // namespace
 
 void ServiceWorkerMetrics::CountInitDiskCacheResult(bool result) {
@@ -113,13 +138,35 @@ void ServiceWorkerMetrics::RecordInstallEventStatus(
                             SERVICE_WORKER_ERROR_MAX_VALUE);
 }
 
-void ServiceWorkerMetrics::RecordEventStatus(size_t fired_events,
-                                             size_t handled_events) {
-  if (!fired_events)
+void ServiceWorkerMetrics::RecordPerWorkerEventHandledStatus(
+    const GURL& scope,
+    EventType event,
+    size_t fired_events,
+    size_t handled_events) {
+  if (!fired_events || IsGoogleLikeScope(scope))
+    return;
+  PerWorkerEventHandledStatus status = SOME_EVENTS_HANDLED;
+  if (fired_events == handled_events)
+    status = ALL_EVENTS_HANDLED;
+  else if (handled_events == 0)
+    status = NO_EVENTS_HANDLED;
+  // For now Fetch is the only type that is recorded.
+  DCHECK_EQ(EVENT_TYPE_FETCH, event);
+  UMA_HISTOGRAM_ENUMERATION("ServiceWorker.EventHandledStatus.PerWorker.Fetch",
+                            status, PER_WORKER_EVENT_HANDLED_STATUS_MAX);
+}
+
+void ServiceWorkerMetrics::RecordEventHandledStatus(const GURL& scope,
+                                                    EventType event,
+                                                    bool handled) {
+  if (IsGoogleLikeScope(scope))
     return;
-  int unhandled_ratio = (fired_events - handled_events) * 100 / fired_events;
-  UMA_HISTOGRAM_PERCENTAGE("ServiceWorker.UnhandledEventRatio",
-                           unhandled_ratio);
+  EventHandledStatus handled_status =
+      handled ? EVENT_HANDLED : EVENT_NOT_HANDLED;
+  // For now Fetch is the only type that is recorded.
+  DCHECK_EQ(EVENT_TYPE_FETCH, event);
+  UMA_HISTOGRAM_ENUMERATION("ServiceWorker.EventHandledStatus.Fetch",
+                            handled_status, EVENT_HANDLED_STATUS_MAX);
 }
 
 void ServiceWorkerMetrics::RecordFetchEventStatus(