sync: Start moving away from PREV_ID and NEXT_ID

sync/syncable/entry.cc

 // Copyright 2012 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 "sync/syncable/entry.h"
 
 #include <iomanip>
 
 #include "base/json/string_escape.h"
 #include "sync/syncable/blob.h"
@@ skipping 77 matching lines @@
   if (IsRoot())
     return TOP_LEVEL_FOLDER;
   // Loose check for server-created top-level folders that aren't
   // bound to a particular model type.
   if (!Get(UNIQUE_SERVER_TAG).empty() && Get(IS_DIR))
     return TOP_LEVEL_FOLDER;
 
   return UNSPECIFIED;
 }
 
+Id Entry::GetPredecessorId() const {
+  return kernel_->ref(PREV_ID);
+}
+
+Id Entry::GetSuccessorId() const {
+  return kernel_->ref(NEXT_ID);
+}
+
 std::ostream& operator<<(std::ostream& s, const Blob& blob) {
   for (Blob::const_iterator i = blob.begin(); i != blob.end(); ++i)
     s << std::hex << std::setw(2)
       << std::setfill('0') << static_cast<unsigned int>(*i);
   return s << std::dec;
 }
 
 std::ostream& operator<<(std::ostream& os, const Entry& entry) {
   int i;
   EntryKernel* const kernel = entry.kernel_;
@@ skipping 34 matching lines @@
   os << "TempFlags: ";
   for ( ; i < BIT_TEMPS_END; ++i) {
     if (kernel->ref(static_cast<BitTemp>(i)))
       os << "#" << i - BIT_TEMPS_BEGIN << ", ";
   }
   return os;
 }
 
 }  // namespace syncable
 }  // namespace syncer