Remove unused member from CacheCounter

Bug: 837333
Change-Id: Idf0f6723d4bc0c771bd6a415bff2269fdef40e06
Reviewed-on: https://chromium-review.googlesource.com/1040206Reviewed-by: Bernhard Bauer <bauerb@chromium.org>
Commit-Queue: Helen Li <xunjieli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#555703}

chrome/browser/browsing_data/counters/cache_counter.h

@@ -12,10 +12,6 @@
 
 class Profile;
 
-namespace browsing_data {
-class ConditionalCacheCountingHelper;
-}
-
 class CacheCounter : public browsing_data::BrowsingDataCounter {
  public:
   class CacheResult : public FinishedResult {
@@ -43,8 +39,6 @@ class CacheCounter : public browsing_data::BrowsingDataCounter {
  private:
   void Count() override;
   void OnCacheSizeCalculated(bool is_upper_limit, int64_t cache_bytes);
-  void FetchEstimate(
-      base::WeakPtr<browsing_data::ConditionalCacheCountingHelper>);
 
   Profile* profile_;
   int64_t calculated_size_;