Moved NavigationManagerImpl serialization out of CRWSessionController.

ios/web/web_state/web_state_impl.h

Index: ios/web/web_state/web_state_impl.h
diff --git a/ios/web/web_state/web_state_impl.h b/ios/web/web_state/web_state_impl.h
index 2e6d0d379ab421079ff7e3b12fec6cebadd05623..5fb1dc2062898425d38fa5a09db2ad9a5a17c4cc 100644
--- a/ios/web/web_state/web_state_impl.h
+++ b/ios/web/web_state/web_state_impl.h
@@ -25,6 +25,7 @@
 #import "ios/web/public/web_state/web_state_delegate.h"
 #include "url/gurl.h"
 
+@class CRWNavigationManagerStorage;
 @class CRWWebController;
 @protocol CRWWebViewProxy;
 @class NSURLRequest;
@@ -62,7 +63,11 @@ class WebUIIOS;
 //    writing them out for session saves.
 class WebStateImpl : public WebState, public NavigationManagerDelegate {
  public:
+  // Constructor for WebStateImpls created for new sessions.
   WebStateImpl(BrowserState* browser_state);
+  // Constructor for WebStatesImpls created for deserialized sessions
+  WebStateImpl(BrowserState* browser_state,
+               CRWNavigationManagerStorage* session_storage);
   ~WebStateImpl() override;
 
   // Gets/Sets the CRWWebController that backs this object.
@@ -73,13 +78,6 @@ class WebStateImpl : public WebState, public NavigationManagerDelegate {
   WebStateFacadeDelegate* GetFacadeDelegate() const;
   void SetFacadeDelegate(WebStateFacadeDelegate* facade_delegate);
 
-  // Returns a WebStateImpl that doesn't have a browser context, web
-  // controller, or facade set, but which otherwise has the same state variables
-  // as the calling object (including copies of the NavigationManager and its
-  // attendant CRWSessionController).
-  // TODO(crbug.com/546377): Clean up this method.
-  WebStateImpl* CopyForSessionWindow();
-
   // Notifies the observers that a provisional navigation has started.
   void OnProvisionalNavigationStarted(const GURL& url);
 
@@ -206,6 +204,7 @@ class WebStateImpl : public WebState, public NavigationManagerDelegate {
   void Stop() override;
   const NavigationManager* GetNavigationManager() const override;
   NavigationManager* GetNavigationManager() override;
+  CRWNavigationManagerStorage* BuildSerializedNavigationManager() override;
   CRWJSInjectionReceiver* GetJSInjectionReceiver() const override;
   void ExecuteJavaScript(const base::string16& javascript) override;
   void ExecuteJavaScript(const base::string16& javascript,
@@ -309,7 +308,8 @@ class WebStateImpl : public WebState, public NavigationManagerDelegate {
   // The CRWWebController that backs this object.
   base::scoped_nsobject<CRWWebController> web_controller_;
 
-  NavigationManagerImpl navigation_manager_;
+  // The NavigationManagerImpl that stores session info for this WebStateImpl.
+  std::unique_ptr<NavigationManagerImpl> navigation_manager_;
 
   // |web::WebUIIOS| object for the current page if it is a WebUI page that
   // uses the web-based WebUI framework, or nullptr otherwise.