sync: Add ControlPreference protobuf and supporting code

chrome/browser/sync/test_profile_sync_service.cc

Index: chrome/browser/sync/test_profile_sync_service.cc
diff --git a/chrome/browser/sync/test_profile_sync_service.cc b/chrome/browser/sync/test_profile_sync_service.cc
index 978b7ef2c88959973b0b8efbe3937ac23da4b68a..4a15312b01e8047a1e1f5dafa710908b07f92150 100644
--- a/chrome/browser/sync/test_profile_sync_service.cc
+++ b/chrome/browser/sync/test_profile_sync_service.cc
@@ -26,9 +26,10 @@ using syncer::sessions::SyncSessionSnapshot;
 using syncer::sessions::SyncSourceInfo;
 using syncer::UserShare;
 using syncer::syncable::Directory;
-using syncer::NIGORI;
 using syncer::DEVICE_INFO;
 using syncer::EXPERIMENTS;
+using syncer::NIGORI;
+using syncer::PRIORITY_PREFERENCES;
 
 namespace browser_sync {
 
@@ -136,7 +137,7 @@ void SyncBackendHostForProfileSyncTest
     if (!directory->InitialSyncEndedForType(NIGORI)) {
       syncer::TestUserShare::CreateRoot(NIGORI, user_share);
 
-      // A side effect of adding the NIGORI mode (normally done by the
+      // A side effect of adding the NIGORI node (normally done by the
       // syncer) is a decryption attempt, which will fail the first time.
     }
 
@@ -148,6 +149,10 @@ void SyncBackendHostForProfileSyncTest
       syncer::TestUserShare::CreateRoot(EXPERIMENTS, user_share);
     }
 
+    if (!directory->InitialSyncEndedForType(PRIORITY_PREFERENCES)) {
+      syncer::TestUserShare::CreateRoot(PRIORITY_PREFERENCES, user_share);
+    }
+
     restored_types = syncer::ModelTypeSet::All();
   }