Tied up BlimpNavigationController to NavigationFeature

blimp/client/core/public/blimp_navigation_controller.h

Index: blimp/client/core/public/blimp_navigation_controller.h
diff --git a/blimp/client/core/public/blimp_navigation_controller.h b/blimp/client/core/public/blimp_navigation_controller.h
index fc79b068f21269eac92283111750522dcb009f72..1568b819dc9cd7fb104f7c292521a2594127c0c9 100644
--- a/blimp/client/core/public/blimp_navigation_controller.h
+++ b/blimp/client/core/public/blimp_navigation_controller.h
@@ -25,6 +25,11 @@ class BlimpNavigationController {
   // Calls to LoadURL informs the engine that it should start navigating to the
   // provided |url|.
   virtual void LoadURL(const GURL& url) = 0;
+  virtual void Reload() = 0;
+  virtual bool CanGoBack() const = 0;
+  virtual bool CanGoForward() const = 0;
+  virtual void GoBack() = 0;
+  virtual void GoForward() = 0;
 
   // Retrieves the URL of the currently selected item in the navigation list.
   virtual const GURL& GetURL() = 0;