Tied up BlimpNavigationController to NavigationFeature

blimp/client/feature/navigation_feature.h

Index: blimp/client/feature/navigation_feature.h
diff --git a/blimp/client/feature/navigation_feature.h b/blimp/client/feature/navigation_feature.h
index c5dd226601592bb05823749ce1e61d3d99ab2917..d71c1c295d54626fa37fa88581e486a3c5ecb053 100644
--- a/blimp/client/feature/navigation_feature.h
+++ b/blimp/client/feature/navigation_feature.h
@@ -48,18 +48,22 @@ class NavigationFeature : public BlimpMessageProcessor {
   void SetDelegate(int tab_id, NavigationFeatureDelegate* delegate);
   void RemoveDelegate(int tab_id);
 
-  void NavigateToUrlText(int tab_id, const std::string& url_text);
-  void Reload(int tab_id);
-  void GoForward(int tab_id);
-  void GoBack(int tab_id);
+  // virtual for testing.
+  virtual void NavigateToUrlText(int tab_id, const std::string& url_text);
+  virtual void Reload(int tab_id);
+  virtual void GoForward(int tab_id);
+  virtual void GoBack(int tab_id);
 
   // BlimpMessageProcessor implementation.
   void ProcessMessage(std::unique_ptr<BlimpMessage> message,
                       const net::CompletionCallback& callback) override;
 
- private:
+ protected:
+  // Finds the NavigationFeatureDelegate for a |tab_id|, protected for unit
+  // tests.
   NavigationFeatureDelegate* FindDelegate(const int tab_id);
 
+ private:
   typedef base::SmallMap<std::map<int, NavigationFeatureDelegate*>> DelegateMap;
 
   DelegateMap delegates_;