[iOS] Refactoring web CRWSessionController user agent code.

ios/web/navigation/navigation_manager_impl.h

Index: ios/web/navigation/navigation_manager_impl.h
diff --git a/ios/web/navigation/navigation_manager_impl.h b/ios/web/navigation/navigation_manager_impl.h
index cf1b29562b7eca3487604784d65e6a613354ca0e..b26e1305a8ecfd1f63d1541302777c466529a05e 100644
--- a/ios/web/navigation/navigation_manager_impl.h
+++ b/ios/web/navigation/navigation_manager_impl.h
@@ -82,6 +82,17 @@ class NavigationManagerImpl : public NavigationManager {
                const Referrer& referrer,
                ui::PageTransition type);
 
+  // Add a new item with the given url, referrer, and navigation type, making it
+  // the current item. If pending item is the same as the current item, this
+  // does nothing. |referrer| may be nil if there isn't one. The item starts
+  // out as pending, and will be lost unless |-commitPendingItem| is called.
+  void AddUserInitiatedPendingItem(const GURL& url,
+                                   const web::Referrer& referrer,
+                                   ui::PageTransition type);
+  void AddRendererInitiatedPendingItem(const GURL& url,
+                                       const web::Referrer& referrer,
+                                       ui::PageTransition type);
+
   // Convenience accessors to get the underlying NavigationItems from the
   // SessionEntries returned from |session_controller_|'s -lastUserEntry and
   // -previousEntry methods.
@@ -119,6 +130,8 @@ class NavigationManagerImpl : public NavigationManager {
   void GoForward() override;
   void GoToIndex(int index) override;
   void Reload(bool check_for_reposts) override;
+  // Removes this method once crbug.com/692303 is fixed.

[kkhorimoto, 2017/02/15 23:02:06]

This comment isn't really necessary since it's already in navigation_manager.h

[liaoyuke, 2017/02/16 01:49:05]

Done.

+  void OverrideDesktopUserAgentForNextPendingItem() override;
 
   // Returns the current list of transient url rewriters, passing ownership to
   // the caller.
@@ -150,6 +163,20 @@ class NavigationManagerImpl : public NavigationManager {
   // |index| has ui::PAGE_TRANSITION_IS_REDIRECT_MASK.
   bool IsRedirectItemAtIndex(int index) const;
 
+  // Add a new item with the given url, referrer, and navigation type, making it
+  // the current item. If pending item is the same as the current item, this
+  // does nothing. |referrer| may be nil if there isn't one. The item starts
+  // out as pending, and will be lost unless |-commitPendingItem| is called.
+  void AddPendingItem(const GURL& url,

[kkhorimoto, 2017/02/15 23:02:06]

Why not just expose this in the public interface instead of creating two
functions above?

[liaoyuke, 2017/02/16 01:49:05]

I feel like having a boolean value as a function parameter is error prone in
C++. In Objective C, by calling the function, you would easily know that the
name of the parameter is rendererInitiated, but in C++, you just pass in the
parameter, and someone may easily mistaken the parameter name as userInitiated.

What do you think?

+                      const web::Referrer& referrer,
+                      ui::PageTransition type,
+                      bool rendererInitiated);

[kkhorimoto, 2017/02/15 23:02:06]

s/rendererInitiated/renderer_initiated

[liaoyuke, 2017/02/16 01:49:05]

Done.

+
+  // If true, override navigation item's useDesktopUserAgent flag and always
+  // create the pending entry using the desktop user agent.
+  // Removes this method once crbug.com/692303 is fixed.
+  bool override_desktop_user_agent_for_next_pending_item_;
+
   // The primary delegate for this manager.
   NavigationManagerDelegate* delegate_;