[Sync] Move //components/sync to the syncer namespace, take 2.

components/browsing_data/core/counters/history_counter.h

Index: components/browsing_data/core/counters/history_counter.h
diff --git a/components/browsing_data/core/counters/history_counter.h b/components/browsing_data/core/counters/history_counter.h
index 48b6fa0949cf9e5eeb064451d614e362c7019526..dd3db2f85e856b81893b9f5882f2a7651d0a0bd2 100644
--- a/components/browsing_data/core/counters/history_counter.h
+++ b/components/browsing_data/core/counters/history_counter.h
@@ -5,6 +5,8 @@
 #ifndef COMPONENTS_BROWSING_DATA_CORE_COUNTERS_HISTORY_COUNTER_H_
 #define COMPONENTS_BROWSING_DATA_CORE_COUNTERS_HISTORY_COUNTER_H_
 
+#include <memory>
+
 #include "base/task/cancelable_task_tracker.h"
 #include "base/timer/timer.h"
 #include "components/browsing_data/core/counters/browsing_data_counter.h"
@@ -16,7 +18,7 @@
 namespace browsing_data {
 
 class HistoryCounter : public browsing_data::BrowsingDataCounter,
-                       public sync_driver::SyncServiceObserver {
+                       public syncer::SyncServiceObserver {
  public:
   typedef base::Callback<history::WebHistoryService*()>
       GetUpdatedWebHistoryServiceCallback;
@@ -36,7 +38,7 @@ class HistoryCounter : public browsing_data::BrowsingDataCounter,
 
   explicit HistoryCounter(history::HistoryService* history_service,
                           const GetUpdatedWebHistoryServiceCallback& callback,
-                          sync_driver::SyncService* sync_service);
+                          syncer::SyncService* sync_service);
   ~HistoryCounter() override;
 
   void OnInitialized() override;
@@ -62,7 +64,7 @@ class HistoryCounter : public browsing_data::BrowsingDataCounter,
 
   GetUpdatedWebHistoryServiceCallback web_history_service_callback_;
 
-  sync_driver::SyncService* sync_service_;
+  syncer::SyncService* sync_service_;
 
   bool has_synced_visits_;