Sanitize access to services in HistoryCounter.

chrome/browser/browsing_data/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 <limits.h>
 #include <stdint.h>
 
 #include "base/timer/timer.h"
 #include "chrome/browser/browsing_data/history_counter.h"
 #include "chrome/browser/history/history_service_factory.h"
@@ skipping 12 matching lines @@
 HistoryCounter::HistoryCounter() : pref_name_(prefs::kDeleteBrowsingHistory),
                                    has_synced_visits_(false),
                                    local_counting_finished_(false),
                                    web_counting_finished_(false),
                                    testing_web_history_service_(nullptr),
                                    sync_service_(nullptr),
                                    history_sync_enabled_(false) {
 }
 
 HistoryCounter::~HistoryCounter() {
-  DCHECK(sync_service_);
-  sync_service_->RemoveObserver(this);
+  if (sync_service_)
+    sync_service_->RemoveObserver(this);
 }
 
 void HistoryCounter::OnInitialized() {
   sync_service_ = ProfileSyncServiceFactory::GetForProfile(GetProfile());
-  DCHECK(sync_service_);
-  sync_service_->AddObserver(this);
+  if (sync_service_)
+    sync_service_->AddObserver(this);
   history_sync_enabled_ =
       !!WebHistoryServiceFactory::GetForProfile(GetProfile());
 }
 
 const std::string& HistoryCounter::GetPrefName() const {
   return pref_name_;
 }
 
 bool HistoryCounter::HasTrackedTasks() {
   return cancelable_task_tracker_.HasTrackedTasks();
 }
 
 void HistoryCounter::SetWebHistoryServiceForTesting(
     history::WebHistoryService* service) {
   testing_web_history_service_ = service;
 }
 
 void HistoryCounter::Count() {
   // Reset the state.
   cancelable_task_tracker_.TryCancelAll();
   web_history_request_.reset();
   has_synced_visits_ = false;
 
   // Count the locally stored items.
   local_counting_finished_ = false;
 
   history::HistoryService* service =
-      HistoryServiceFactory::GetForProfileWithoutCreating(GetProfile());
+      HistoryServiceFactory::GetForProfile(
+          GetProfile(), ServiceAccessType::EXPLICIT_ACCESS);
 
   service->GetHistoryCount(
       GetPeriodStart(),
       base::Time::Max(),
       base::Bind(&HistoryCounter::OnGetLocalHistoryCount,
                  base::Unretained(this)),
       &cancelable_task_tracker_);
 
   // If the history sync is enabled, test if there is at least one synced item.
   // If the testing web history service is present, use that one instead.
@@ skipping 103 matching lines @@
   bool history_sync_enabled_new_state =
       !!WebHistoryServiceFactory::GetForProfile(GetProfile());
 
   // 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();
   }
 }