Rename VisitDatabaseObserver to HistoryServiceObserver

chrome/browser/history/in_memory_history_backend.cc

Index: chrome/browser/history/in_memory_history_backend.cc
diff --git a/chrome/browser/history/in_memory_history_backend.cc b/chrome/browser/history/in_memory_history_backend.cc
index 928be33b4507d90a1f84c38a82113c1eb64a29f6..633b89e8851e9488a30da0f8fc91e518925cee95 100644
--- a/chrome/browser/history/in_memory_history_backend.cc
+++ b/chrome/browser/history/in_memory_history_backend.cc
@@ -28,7 +28,7 @@ InMemoryHistoryBackend::InMemoryHistoryBackend()
 
 InMemoryHistoryBackend::~InMemoryHistoryBackend() {
   if (history_service_)
-    history_service_->RemoveHistoryServiceObserver(this);
+    history_service_->RemoveObserver(this);
 }
 
 bool InMemoryHistoryBackend::Init(const base::FilePath& history_filename) {
@@ -46,7 +46,7 @@ void InMemoryHistoryBackend::AttachToHistoryService(
 
   DCHECK(history_service);
   history_service_ = history_service;
-  history_service_->AddHistoryServiceObserver(this);
+  history_service_->AddObserver(this);
 
   profile_ = profile;