Fix BrowsingDataCounter race condition

components/browsing_data/core/counters/history_counter.cc

 // 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.
 
 #include "components/browsing_data/core/counters/history_counter.h"
 
 #include <limits.h>
 #include <stdint.h>
 
 #include "base/memory/ptr_util.h"
@@ skipping 37 matching lines @@
 const char* HistoryCounter::GetPrefName() const {
   return GetTab() == ClearBrowsingDataTab::BASIC
              ? browsing_data::prefs::kDeleteBrowsingHistoryBasic
              : browsing_data::prefs::kDeleteBrowsingHistory;
 }
 
 void HistoryCounter::Count() {
   // Reset the state.
   cancelable_task_tracker_.TryCancelAll();
   web_history_request_.reset();
+  weak_ptr_factory_.InvalidateWeakPtrs();
+
   has_synced_visits_ = false;
 
   // Count the locally stored items.
   local_counting_finished_ = false;
 
   history_service_->GetHistoryCount(
       GetPeriodStart(), base::Time::Max(),
       base::Bind(&HistoryCounter::OnGetLocalHistoryCount,
                  weak_ptr_factory_.GetWeakPtr()),
       &cancelable_task_tracker_);
@@ skipping 97 matching lines @@
 
   // If the history sync was just enabled or disabled, restart the counter
   // so that we update the result accordingly.
   if (history_sync_enabled_ != history_sync_enabled_new_state) {
     history_sync_enabled_ = history_sync_enabled_new_state;
     Restart();
   }
 }
 
 }  // namespace browsing_data