Refactor sending NOTIFICATION_HISTORY_URL_VISITED

chrome/browser/history/history_backend.h

Index: chrome/browser/history/history_backend.h
diff --git a/chrome/browser/history/history_backend.h b/chrome/browser/history/history_backend.h
index 819f9df23ac95562c13bf15b6ad70defa82b15b9..fbf0ff32bac9daf64b156f4a4162785a56b3533e 100644
--- a/chrome/browser/history/history_backend.h
+++ b/chrome/browser/history/history_backend.h
@@ -15,6 +15,7 @@
 #include "base/gtest_prod_util.h"
 #include "base/memory/memory_pressure_listener.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/observer_list.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task/cancelable_task_tracker.h"
 #include "chrome/browser/history/expire_history_backend.h"
@@ -49,6 +50,7 @@ class AndroidProviderBackend;
 
 class CommitLaterTask;
 struct DownloadRow;
+class HistoryBackendObserver;
 class HistoryClient;
 class HistoryDBTask;
 class InMemoryHistoryBackend;
@@ -122,12 +124,19 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
 
     // Notify HistoryService that VisitDatabase was changed. The event will be
     // forwarded to the history::HistoryServiceObservers in the UI thread.
-    virtual void NotifyAddVisit(const history::BriefVisitInfo& info) = 0;
+    virtual void NotifyAddVisit(const BriefVisitInfo& info) = 0;
 
     // Notify HistoryService that some URLs favicon changed that will forward
     // the events to the FaviconChangedObservers in the correct thread.
     virtual void NotifyFaviconChanged(const std::set<GURL>& urls) = 0;
 
+    // Notify HistoryService that the user is visiting an URL. The event will
+    // be forwarded to the HistoryServiceObservers in the correct thread.
+    virtual void NotifyURLVisited(ui::PageTransition transition,
+                                  const URLRow& row,
+                                  const RedirectList& redirects,
+                                  base::Time visit_time) = 0;
+
     // Broadcasts the specified notification to the notification service.
     // This is implemented here because notifications must only be sent from
     // the main thread. This is the only method that doesn't identify the
@@ -303,6 +312,11 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
   void DeleteMatchingURLsForKeyword(KeywordID keyword_id,
                                     const base::string16& term);
 
+  // Observers -----------------------------------------------------------------
+
+  void AddObserver(HistoryBackendObserver* observer);
+  void RemoveObserver(HistoryBackendObserver* observer);
+
 #if defined(OS_ANDROID)
   // Android Provider ---------------------------------------------------------
 
@@ -505,6 +519,13 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
  protected:
   virtual ~HistoryBackend();
 
+  // Notify HistoryBackendObserver that |transition| to |row| occurred at
+  // |visit_time| following |redirects| (empty if there is no redirects).
+  void NotifyAddVisit(ui::PageTransition transition,
+                      const URLRow& row,
+                      const RedirectList& redirects,
+                      base::Time visit_time);
+
  private:
   friend class base::RefCountedThreadSafe<HistoryBackend>;
   friend class CommitLaterTask;  // The commit task needs to call Commit().
@@ -889,11 +910,17 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
 
   // Used to manage syncing of the typed urls datatype. This will be NULL
   // before Init is called.
+  // TODO(sdefresne): turn TypedUrlSyncableService into a HistoryBackendObserver
+  // and remove this field since it is only used for forwarding notifications
+  // about URL visited, modified, deleted.
   scoped_ptr<TypedUrlSyncableService> typed_url_syncable_service_;
 
   // Listens for the system being under memory pressure.
   scoped_ptr<base::MemoryPressureListener> memory_pressure_listener_;
 
+  // List of observers
+  ObserverList<HistoryBackendObserver> observers_;
+
   DISALLOW_COPY_AND_ASSIGN(HistoryBackend);
 };