sync: Add ControlPreference protobuf and supporting code

sync/internal_api/write_node.cc

 // Copyright (c) 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/internal_api/public/write_node.h"
 
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "sync/internal_api/public/base_transaction.h"
 #include "sync/internal_api/public/write_transaction.h"
@@ skipping 180 matching lines @@
   SetEntitySpecifics(entity_specifics);
 }
 
 void WriteNode::SetExperimentsSpecifics(
     const sync_pb::ExperimentsSpecifics& new_value) {
   sync_pb::EntitySpecifics entity_specifics;
   entity_specifics.mutable_experiments()->CopyFrom(new_value);
   SetEntitySpecifics(entity_specifics);
 }
 
+void WriteNode::SetPriorityPreferenceSpecifics(
+    const sync_pb::PriorityPreferenceSpecifics& new_value) {
+  sync_pb::EntitySpecifics entity_specifics;
+  entity_specifics.mutable_priority_preference()->CopyFrom(new_value);
+  SetEntitySpecifics(entity_specifics);
+}
+
 void WriteNode::SetEntitySpecifics(
     const sync_pb::EntitySpecifics& new_value) {
   ModelType new_specifics_type =
       GetModelTypeFromSpecifics(new_value);
   DCHECK_NE(new_specifics_type, UNSPECIFIED);
   DVLOG(1) << "Writing entity specifics of type "
            << ModelTypeToString(new_specifics_type);
   // GetModelType() can be unspecified if this is the first time this
   // node is being initialized (see PutModelType()).  Otherwise, it
   // should match |new_specifics_type|.
@@ skipping 295 matching lines @@
   MarkForSyncing();
 
   return true;
 }
 
 void WriteNode::MarkForSyncing() {
   syncable::MarkForSyncing(entry_);
 }
 
 }  // namespace syncer