[Offline Pages] Add cached offline page utils and show usage in settings.

chrome/browser/browsing_data/cache_counter.h

 // Copyright (c) 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 CHROME_BROWSER_BROWSING_DATA_CACHE_COUNTER_H_
 #define CHROME_BROWSER_BROWSING_DATA_CACHE_COUNTER_H_
 
 #include <stdint.h>
 
 #include "base/memory/weak_ptr.h"
@@ skipping 24 matching lines @@
     DISALLOW_COPY_AND_ASSIGN(CacheResult);
   };
 
   explicit CacheCounter(Profile* profile);
   ~CacheCounter() override;
 
   const char* GetPrefName() const override;
 
  private:
   void Count() override;
-  void OnCacheSizeCalculated(int64_t bytes, bool is_upper_limit);
+  void OnCacheSizeCalculated(bool is_upper_limit, int64_t cache_bytes);
   void FetchEstimate(
       base::WeakPtr<browsing_data::ConditionalCacheCountingHelper>);
 
   Profile* profile_;
-  bool pending_;
+  int64_t calculated_size_;
+  bool is_upper_limit_;
+  int pending_sources_;
 
   base::WeakPtrFactory<CacheCounter> weak_ptr_factory_;
-
 };
 
 #endif  // CHROME_BROWSER_BROWSING_DATA_CACHE_COUNTER_H_