Add PrerenderLocalPredictor, which will eventually perform

chrome/browser/history/visit_database.cc

Index: chrome/browser/history/visit_database.cc
===================================================================
--- chrome/browser/history/visit_database.cc	(revision 131579)
+++ chrome/browser/history/visit_database.cc	(working copy)
@@ -24,7 +24,8 @@
 
 namespace history {
 
-VisitDatabase::VisitDatabase() {
+VisitDatabase::VisitDatabase() :
+    observers_(new ObserverListThreadSafe<VisitDatabaseObserver>()) {
 }
 
 VisitDatabase::~VisitDatabase() {
@@ -158,6 +159,12 @@
     }
   }
 
+  BriefVisitInfo info;
+  info.url_id = visit->url_id;
+  info.time = visit->visit_time;
+  info.transition = visit->transition;
+  observers_->Notify(&VisitDatabaseObserver::OnAddVisit, info);
+
   return visit->visit_id;
 }
 
@@ -558,4 +565,36 @@
   return true;
 }
 
+void VisitDatabase::AddVisitDatabaseObserver(VisitDatabaseObserver* observer) {
+  observers_->AddObserver(observer);
+}
+
+void VisitDatabase::RemoveVisitDatabaseObserver(
+    VisitDatabaseObserver* observer) {
+  observers_->RemoveObserver(observer);
+}
+
+void VisitDatabase::GetBriefVisitInfoOfMostRecentVisits(
+    int max_visits,
+    std::vector<BriefVisitInfo>* result_vector) {
+  result_vector->clear();
+
+  sql::Statement statement(GetDB().GetCachedStatement(SQL_FROM_HERE,
+      "SELECT url,visit_time,transition FROM visits "
+      "ORDER BY id DESC LIMIT ?"));
+
+  statement.BindInt64(0, max_visits);
+
+  if (!statement.is_valid())
+    return;
+
+  while (statement.Step()) {
+    BriefVisitInfo info;
+    info.url_id = statement.ColumnInt64(0);
+    info.time = base::Time::FromInternalValue(statement.ColumnInt64(1));
+    info.transition = content::PageTransitionFromInt(statement.ColumnInt(2));
+    result_vector->push_back(info);
+  }
+}
+
 }  // namespace history