ServiceWorker: Add UMA for storage recovery operation

content/browser/service_worker/service_worker_metrics.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_METRICS_H_
 #define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_METRICS_H_
 
 #include "base/macros.h"
 #include "content/browser/service_worker/service_worker_database.h"
 
@@ skipping 10 matching lines @@
     NUM_READ_RESPONSE_RESULT_TYPES,
   };
 
   enum WriteResponseResult {
     WRITE_OK,
     WRITE_HEADERS_ERROR,
     WRITE_DATA_ERROR,
     NUM_WRITE_RESPONSE_RESULT_TYPES,
   };
 
+  enum DeleteAndStartOverResult {
+    DELETE_OK,
+    DELETE_DATABASE_ERROR,
+    DELETE_DISK_CACHE_ERROR,
+    NUM_DELETE_AND_START_OVER_RESULT_TYPES,
+  };
+
   // Used for ServiceWorkerDiskCache.
   static void CountInitDiskCacheResult(bool result);
   static void CountReadResponseResult(ReadResponseResult result);
   static void CountWriteResponseResult(WriteResponseResult result);
 
   // Used for ServiceWorkerDatabase.
   static void CountOpenDatabaseResult(ServiceWorkerDatabase::Status status);
   static void CountReadDatabaseResult(ServiceWorkerDatabase::Status status);
   static void CountWriteDatabaseResult(ServiceWorkerDatabase::Status status);
+  static void RecordDestroyDatabaseResult(ServiceWorkerDatabase::Status status);
+
+  // Used for ServiceWorkerStorage.
+  static void RecordDeleteAndStartOverResult(DeleteAndStartOverResult result);
 
   // Counts the number of page loads controlled by a Service Worker.
   static void CountControlledPageLoad(const GURL& url);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ServiceWorkerMetrics);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_METRICS_H_