Created SerializedUserDataManager.

ios/web/navigation/crw_serialized_navigation_manager.mm

Index: ios/web/navigation/crw_serialized_navigation_manager.mm
diff --git a/ios/web/navigation/crw_serialized_navigation_manager.mm b/ios/web/navigation/crw_serialized_navigation_manager.mm
index ea90d7fdae65cb7fb81b275cfcb8362cd688f530..3f8560b644a5cd4d332ed8429018a1c9129395c4 100644
--- a/ios/web/navigation/crw_serialized_navigation_manager.mm
+++ b/ios/web/navigation/crw_serialized_navigation_manager.mm
@@ -5,6 +5,7 @@
 #import "ios/web/navigation/crw_serialized_navigation_manager.h"
 
 #include "base/mac/objc_property_releaser.h"
+#include "base/mac/scoped_nsobject.h"
 #import "ios/web/navigation/crw_session_certificate_policy_manager.h"
 
 namespace {
@@ -20,9 +21,15 @@ NSString* const kPreviousNavigationIndexKey = @"previousNavigationIndex";
 NSString* const kTabIDKey = @"tabId";
 NSString* const kWindowNameKey = @"windowName";
 NSString* const kXCallbackParametersKey = @"xCallbackParameters";
+NSString* const kSerializedUserDataKey = @"serializedUserData";
 }
 
 @interface CRWSerializedNavigationManager () {
+  // |serializedUserData| is backed with an NSMutableDictionary so that
+  // NavigationManager's legacy properties can be decoded and added directly to
+  // the dictionary.
+  base::scoped_nsobject<NSMutableDictionary> _serializedUserData;
+
   base::mac::ObjCPropertyReleaser
       _propertyReleaser_CRWSerializedNavigationManager;
 }
@@ -79,6 +86,8 @@ NSString* const kXCallbackParametersKey = @"xCallbackParameters";
     }
     _XCallbackParameters =
         [[decoder decodeObjectForKey:kXCallbackParametersKey] retain];
+    _serializedUserData.reset([[NSMutableDictionary alloc] initWithDictionary:
+        [decoder decodeObjectForKey:kSerializedUserDataKey]]);
   }
   return self;
 }
@@ -100,6 +109,16 @@ NSString* const kXCallbackParametersKey = @"xCallbackParameters";
                forKey:kCertificatePolicyManagerKey];
   [coder encodeObject:self.XCallbackParameters forKey:kXCallbackParametersKey];
   // rendererInitiated is deliberately not preserved, as upstream.
+  [coder encodeObject:self.serializedUserData forKey:kSerializedUserDataKey];
+}
+
+- (void)setSerializedUserData:(NSDictionary*)serializedUserData {
+  _serializedUserData.reset(
+      [[NSMutableDictionary alloc] initWithDictionary:serializedUserData]);
+}
+
+- (NSDictionary*)serializedUserData {
+  return _serializedUserData;

[Eugene But (OOO till 7-30), 2015/09/24 21:39:25]

NIT: Maybe return an autoreleased copy here (same as in
GetSerializationDictionary)?

 }
 
 @end