Created SerializedUserDataManager.

ios/web/public/navigation_manager.h

Index: ios/web/public/navigation_manager.h
diff --git a/ios/web/public/navigation_manager.h b/ios/web/public/navigation_manager.h
index 1798197d2df8e8ae267360d84ad5c5430e5533f4..93f6d692545f860d214fa77a3ffb09992fbd7f50 100644
--- a/ios/web/public/navigation_manager.h
+++ b/ios/web/public/navigation_manager.h
@@ -5,6 +5,7 @@
 #ifndef IOS_WEB_PUBLIC_NAVIGATION_MANAGER_H_
 #define IOS_WEB_PUBLIC_NAVIGATION_MANAGER_H_
 
+#include "base/supports_user_data.h"
 #include "ios/web/public/browser_url_rewriter.h"
 
 namespace web {
@@ -18,9 +19,9 @@ class WebState;
 //
 // Each NavigationManager belongs to one WebState; each WebState has
 // exactly one NavigationManager.
-class NavigationManager {
+class NavigationManager : public base::SupportsUserData {

[Eugene But (OOO till 7-30), 2015/09/24 17:05:07]

Is there any specific reason why NavigationManager is a base::SupportsUserData
subclass? Can you make NavigationManagerImpl support user data?

[kkhorimoto, 2015/09/24 21:24:29]

I initially did this because of the style guide's rules on multiple inheritance
in C++ (SupportsUserData is not a pure interface).  However, I've updated the
implementation to simply use the web state's user data.

  public:
-  virtual ~NavigationManager() {}
+  ~NavigationManager() override {}
 
   // Gets the BrowserState associated with this NavigationManager. Can never
   // return null.