Changed DB to store node positions as Ordinals.

sync/syncable/entry_kernel.h

Index: sync/syncable/entry_kernel.h
diff --git a/sync/syncable/entry_kernel.h b/sync/syncable/entry_kernel.h
index 383ffd71c00349b1136f3ea0fbc5a7474dd351a5..e8c0924b577fb52ef7326e5fb6516424e7286363 100644
--- a/sync/syncable/entry_kernel.h
+++ b/sync/syncable/entry_kernel.h
@@ -8,6 +8,7 @@
 #include "base/time.h"
 #include "base/values.h"
 #include "sync/internal_api/public/base/model_type.h"
+#include "sync/internal_api/public/base/node_ordinal.h"
 #include "sync/internal_api/public/util/immutable.h"
 #include "sync/protocol/sync.pb.h"
 #include "sync/syncable/metahandle_set.h"
@@ -21,8 +22,8 @@ namespace syncable {
 //  - EntryKernel struct in this file
 //  - syncable_columns.h
 //  - syncable_enum_conversions{.h,.cc,_unittest.cc}
-//  - EntryKernel::EntryKernel(), EntryKernel::ToValue(), operator<<
-//    for Entry in syncable.cc
+//  - EntryKernel::EntryKernel(), EntryKernel::ToValue() in entry_kernel.cc
+//  - operator<< in Entry.cc
 //  - BindFields() and UnpackEntry() in directory_backing_store.cc
 //  - TestSimpleFieldsPreservedDuringSaveChanges in syncable_unittest.cc
 
@@ -47,14 +48,8 @@ enum BaseVersion {
 
 enum Int64Field {
   SERVER_VERSION = BASE_VERSION + 1,
-
-  // A numeric position value that indicates the relative ordering of
-  // this object among its siblings.
-  SERVER_POSITION_IN_PARENT,
-
   LOCAL_EXTERNAL_ID,  // ID of an item in the external local storage that this
                       // entry is associated with. (such as bookmarks.js)
-
   INT64_FIELDS_END
 };
 
@@ -143,9 +138,22 @@ enum ProtoField {
 };
 
 enum {
-  FIELD_COUNT = PROTO_FIELDS_END,
+  PROTO_FIELDS_COUNT = PROTO_FIELDS_END - PROTO_FIELDS_BEGIN,
+  ORDINAL_FIELDS_BEGIN = PROTO_FIELDS_END
+};
+
+enum OrdinalField {
+  // An Ordinal that identifies the relative ordering of this object
+  // among its siblings.
+  SERVER_ORDINAL_IN_PARENT = ORDINAL_FIELDS_BEGIN,
+  ORDINAL_FIELDS_END
+};
+
+enum {
+  ORDINAL_FIELDS_COUNT = ORDINAL_FIELDS_END - ORDINAL_FIELDS_BEGIN,
+  FIELD_COUNT = ORDINAL_FIELDS_END - BEGIN_FIELDS,
   // Past this point we have temporaries, stored in memory only.
-  BEGIN_TEMPS = PROTO_FIELDS_END,
+  BEGIN_TEMPS = ORDINAL_FIELDS_END,
   BIT_TEMPS_BEGIN = BEGIN_TEMPS,
 };
 
@@ -160,9 +168,6 @@ enum {
   BIT_TEMPS_COUNT = BIT_TEMPS_END - BIT_TEMPS_BEGIN
 };
 
-enum {
-  PROTO_FIELDS_COUNT = PROTO_FIELDS_END - PROTO_FIELDS_BEGIN
-};
 
 
 struct EntryKernel {
@@ -172,6 +177,7 @@ struct EntryKernel {
   int64 int64_fields[INT64_FIELDS_COUNT];
   base::Time time_fields[TIME_FIELDS_COUNT];
   Id id_fields[ID_FIELDS_COUNT];
+  NodeOrdinal ordinal_fields[ORDINAL_FIELDS_COUNT];
   std::bitset<BIT_FIELDS_COUNT> bit_fields;
   std::bitset<BIT_TEMPS_COUNT> bit_temps;
 
@@ -239,6 +245,9 @@ struct EntryKernel {
   inline void put(ProtoField field, const sync_pb::EntitySpecifics& value) {
     specifics_fields[field - PROTO_FIELDS_BEGIN].CopyFrom(value);
   }
+  inline void put(OrdinalField field, const NodeOrdinal& value) {
+    ordinal_fields[field - ORDINAL_FIELDS_BEGIN] = value;
+  }
   inline void put(BitTemp field, bool value) {
     bit_temps[field - BIT_TEMPS_BEGIN] = value;
   }
@@ -274,6 +283,9 @@ struct EntryKernel {
   inline const sync_pb::EntitySpecifics& ref(ProtoField field) const {
     return specifics_fields[field - PROTO_FIELDS_BEGIN];
   }
+  inline const NodeOrdinal& ref(OrdinalField field) const {
+    return ordinal_fields[field - ORDINAL_FIELDS_BEGIN];
+  }
   inline bool ref(BitTemp field) const {
     return bit_temps[field - BIT_TEMPS_BEGIN];
   }
@@ -288,6 +300,9 @@ struct EntryKernel {
   inline Id& mutable_ref(IdField field) {
     return id_fields[field - ID_FIELDS_BEGIN];
   }
+  inline NodeOrdinal& mutable_ref(OrdinalField field) {
+    return ordinal_fields[field - ORDINAL_FIELDS_BEGIN];
+  }
 
   ModelType GetServerModelType() const;