Eliminate NOTIFICATION_HISTORY_LOADED notification

chrome/browser/predictors/autocomplete_action_predictor.h

Index: chrome/browser/predictors/autocomplete_action_predictor.h
diff --git a/chrome/browser/predictors/autocomplete_action_predictor.h b/chrome/browser/predictors/autocomplete_action_predictor.h
index e75cb082e189435082c1ff9cbdb99a689d53b643..af378281f0b74d43c4b0ba1a58560be0e5035cb4 100644
--- a/chrome/browser/predictors/autocomplete_action_predictor.h
+++ b/chrome/browser/predictors/autocomplete_action_predictor.h
@@ -11,8 +11,10 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "base/scoped_observer.h"
 #include "base/strings/string16.h"
 #include "chrome/browser/predictors/autocomplete_action_predictor_table.h"
+#include "components/history/core/browser/history_service_observer.h"
 #include "components/history/core/browser/history_types.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "content/public/browser/navigation_controller.h"
@@ -61,6 +63,7 @@ namespace predictors {
 class AutocompleteActionPredictor
     : public KeyedService,
       public content::NotificationObserver,
+      public history::HistoryServiceObserver,
       public base::SupportsWeakPtr<AutocompleteActionPredictor> {
  public:
   enum Action {
@@ -112,6 +115,12 @@ class AutocompleteActionPredictor
   // abandoned.
   bool IsPrerenderAbandonedForTesting();
 
+  // KeyedService:
+  void Shutdown() override;
+
+  // history::HistoryServiceObserver:
+  void OnHistoryServiceLoaded(HistoryService* history_service) override;
+
  private:
   friend class AutocompleteActionPredictorTest;
   friend class ::PredictorsHandler;
@@ -246,6 +255,9 @@ class AutocompleteActionPredictor
 
   bool initialized_;
 
+  ScopedObserver<HistoryService, HistoryServiceObserver>
+      history_service_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(AutocompleteActionPredictor);
 };