ServiceWorker: Add UMA for ServiceWorkerDiskCache

content/browser/service_worker/service_worker_histograms.h

+// Copyright 2014 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_SERVICE_WORKER_SERVICE_WORKER_HISTOGRAMS_H_
+#define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_HISTOGRAMS_H_
+
+#include "base/macros.h"
+
+namespace content {
+
+class ServiceWorkerHistograms {
+ public:
+  enum ReadResponseResult {
+    READ_OK,
+    READ_HEADERS_ERROR,
+    READ_DATA_ERROR,
+    NUM_READ_RESPONSE_RESULT_TYPES,
+  };
+
+  enum WriteResponseResult {
+    WRITE_OK,
+    WRITE_HEADERS_ERROR,
+    WRITE_DATA_ERROR,
+    NUM_WRITE_RESPONSE_RESULT_TYPES,
+  };
+
+  static void CountInitDiskCacheResult(bool result);
+  static void CountReadResponseResult(ReadResponseResult result);
+  static void CountWriteResponseResult(WriteResponseResult result);
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(ServiceWorkerHistograms);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_HISTOGRAMS_H_