[Background Sync] Gather UMA data for Background Sync

content/browser/background_sync/background_sync_metrics.h

Index: content/browser/background_sync/background_sync_metrics.h
diff --git a/content/browser/background_sync/background_sync_metrics.h b/content/browser/background_sync/background_sync_metrics.h
new file mode 100644
index 0000000000000000000000000000000000000000..5b74ed5e1ca203f333238770bb748c8a373bb847
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+++ b/content/browser/background_sync/background_sync_metrics.h
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+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_BACKGROUND_SYNC_BACKGROUND_SYNC_METRICS_H_
+#define CONTENT_BROWSER_BACKGROUND_SYNC_BACKGROUND_SYNC_METRICS_H_
+
+#include "base/macros.h"
+#include "base/time/time.h"
+#include "content/browser/background_sync/background_sync.pb.h"
+#include "content/browser/background_sync/background_sync_manager.h"
+
+namespace content {
+
+// This class contains the logic for recording usage metrics for the Background
+// Sync API. It is stateless, containing only static methods, so it can be used
+// by any of the Background Sync code, without needing to be instantiated
+// explicitly.
+class BackgroundSyncMetrics {
+ public:
+  enum RegistrationCouldFire {
+    REGISTRATION_COULD_NOT_FIRE,
+    REGISTRATION_COULD_FIRE
+  };
+
+  enum RegistrationIsDuplicate {
+    REGISTRATION_IS_NOT_DUPLICATE,
+    REGISTRATION_IS_DUPLICATE
+  };
+
+  // Records the result of a single sync event firing.
+  static void RecordEventResult(SyncPeriodicity periodicity, bool result);
+
+  // Records the time spent running a batch of sync events.
+  static void RecordBatchSyncEventHandlingTime(const base::TimeDelta& time);
+
+  // Records the result of trying to register a sync. |could_fire| indicates
+  // whether the conditions were sufficient for the sync to fire immediately at
+  // the time it was registered.
+  static void CountRegister(SyncPeriodicity periodicity,
+                            RegistrationCouldFire could_fire,
+                            RegistrationIsDuplicate registration_is_duplicate,
+                            BackgroundSyncManager::ErrorType result);
+
+  // Records the result of trying to unregister a sync.
+  static void CountUnregister(SyncPeriodicity periodicity,
+                              BackgroundSyncManager::ErrorType result);
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(BackgroundSyncMetrics);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_BACKGROUND_SYNC_BACKGROUND_SYNC_METRICS_H_