Move all core files in //components/sessions into core/ subdir

components/sessions/ios/ios_serialized_navigation_driver.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/sessions/ios/ios_serialized_navigation_driver.h"
 
 #include "base/memory/singleton.h"
-#include "components/sessions/serialized_navigation_entry.h"
+#include "components/sessions/core/serialized_navigation_entry.h"
 #include "ios/web/public/referrer.h"
 
 namespace sessions {
 
 namespace {
 const int kObsoleteReferrerPolicyAlways = 0;
 const int kObsoleteReferrerPolicyDefault = 1;
 const int kObsoleteReferrerPolicyNever = 2;
 const int kObsoleteReferrerPolicyOrigin = 3;
 }  // namespace
@@ skipping 111 matching lines @@
     navigation->referrer_policy_ = GetDefaultReferrerPolicy();
   }
 }
 
 std::string IOSSerializedNavigationDriver::StripReferrerFromPageState(
       const std::string& page_state) const {
   return std::string();
 }
 
 }  // namespace sessions