Moved NavigationManagerImpl serialization out of CRWSessionController.

ios/web/public/web_state/web_state.h

Index: ios/web/public/web_state/web_state.h
diff --git a/ios/web/public/web_state/web_state.h b/ios/web/public/web_state/web_state.h
index cb31708c492e1c35c175c38871a1731f9e39ba58..75f6e79774bd69fbf482fe967ef4ddb5c2fc80d5 100644
--- a/ios/web/public/web_state/web_state.h
+++ b/ios/web/public/web_state/web_state.h
@@ -24,6 +24,7 @@ class GURL;
 class SkBitmap;
 
 @class CRWJSInjectionReceiver;
+@class CRWNavigationManagerStorage;
 @protocol CRWScrollableContent;
 @protocol CRWWebViewProxy;
 typedef id<CRWWebViewProxy> CRWWebViewProxyType;
@@ -98,6 +99,10 @@ class WebState : public base::SupportsUserData {
 
   // Creates a new WebState.
   static std::unique_ptr<WebState> Create(const CreateParams& params);
+  // Creates a new WebState from a serialized NavigationManager.
+  static std::unique_ptr<WebState> Create(
+      const CreateParams& params,
+      CRWNavigationManagerStorage* session_storage);
 
   ~WebState() override {}
 
@@ -135,6 +140,10 @@ class WebState : public base::SupportsUserData {
   virtual const NavigationManager* GetNavigationManager() const = 0;
   virtual NavigationManager* GetNavigationManager() = 0;
 
+  // Creates a serialized version of the NavigationManager. The returned value
+  // is autoreleased.
+  virtual CRWNavigationManagerStorage* BuildSerializedNavigationManager() = 0;
+
   // Gets the CRWJSInjectionReceiver associated with this WebState.
   virtual CRWJSInjectionReceiver* GetJSInjectionReceiver() const = 0;