Histogram appcache task queue and run times.

webkit/appcache/appcache_histograms.h

 // Copyright (c) 2011 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 WEBKIT_APPCACHE_APPCACHE_HISTOGRAMS_H_
 #define WEBKIT_APPCACHE_APPCACHE_HISTOGRAMS_H_
 #pragma once
 
 #include "base/basictypes.h"
 
+namespace base {
+class TimeDelta;
+}
+
 namespace appcache {
 
 class AppCacheHistograms {
  public:
   enum InitResultType {
     INIT_OK, SQL_DATABASE_ERROR, DISK_CACHE_ERROR,
     NUM_INIT_RESULT_TYPES
   };
   static void CountInitResult(InitResultType init_result);
 
   enum CheckResponseResultType {
     RESPONSE_OK, MANIFEST_OUT_OF_DATE, RESPONSE_OUT_OF_DATE, ENTRY_NOT_FOUND,
     READ_HEADERS_ERROR, READ_DATA_ERROR, UNEXPECTED_DATA_SIZE, CHECK_CANCELED,
     NUM_CHECK_RESPONSE_RESULT_TYPES
   };
   static void CountCheckResponseResult(CheckResponseResultType result);
 
+  static void AddTaskQueueTimeSample(const base::TimeDelta& duration);
+  static void AddTaskRunTimeSample(const base::TimeDelta& duration);
+  static void AddTaskCompletionTimeSample(const base::TimeDelta& duration);
+
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(AppCacheHistograms);
 };
 
 }  // namespace appcache
 
 #endif  // WEBKIT_APPCACHE_APPCACHE_HISTOGRAMS_H_