Revert 112178 - [Sync] Make syncer commands avoid posting tasks on threads with no work to do

chrome/browser/sync/engine/apply_updates_command.cc

Index: chrome/browser/sync/engine/apply_updates_command.cc
===================================================================
--- chrome/browser/sync/engine/apply_updates_command.cc	(revision 112317)
+++ chrome/browser/sync/engine/apply_updates_command.cc	(working copy)
@@ -17,35 +17,6 @@
 ApplyUpdatesCommand::ApplyUpdatesCommand() {}
 ApplyUpdatesCommand::~ApplyUpdatesCommand() {}
 
-std::set<ModelSafeGroup> ApplyUpdatesCommand::GetGroupsToChange(
-    const sessions::SyncSession& session) const {
-  std::set<ModelSafeGroup> groups_with_unapplied_updates;
-
-  syncable::ModelTypeBitSet server_types_with_unapplied_updates;
-  {
-    syncable::ScopedDirLookup dir(session.context()->directory_manager(),
-                                  session.context()->account_name());
-    if (!dir.good()) {
-      LOG(ERROR) << "Scoped dir lookup failed!";
-      return groups_with_unapplied_updates;
-    }
-
-    syncable::ReadTransaction trans(FROM_HERE, dir);
-    server_types_with_unapplied_updates =
-        dir->GetServerTypesWithUnappliedUpdates(&trans);
-  }
-
-  for (int i = 0; i < syncable::MODEL_TYPE_COUNT; ++i) {
-    const syncable::ModelType type = syncable::ModelTypeFromInt(i);
-    if (server_types_with_unapplied_updates.test(type)) {
-      groups_with_unapplied_updates.insert(
-          GetGroupForModelType(type, session.routing_info()));
-    }
-  }
-
-  return groups_with_unapplied_updates;
-}
-
 void ApplyUpdatesCommand::ModelChangingExecuteImpl(SyncSession* session) {
   syncable::ScopedDirLookup dir(session->context()->directory_manager(),
                                 session->context()->account_name());
@@ -53,27 +24,9 @@
     LOG(ERROR) << "Scoped dir lookup failed!";
     return;
   }
-
   syncable::WriteTransaction trans(FROM_HERE, syncable::SYNCER, dir);
-
-  // Compute server types with unapplied updates that fall under our
-  // group restriction.
-  const syncable::ModelTypeBitSet server_types_with_unapplied_updates =
-      dir->GetServerTypesWithUnappliedUpdates(&trans);
-  syncable::ModelTypeBitSet server_type_restriction;
-  for (int i = 0; i < syncable::MODEL_TYPE_COUNT; ++i) {
-    const syncable::ModelType server_type = syncable::ModelTypeFromInt(i);
-    if (server_types_with_unapplied_updates.test(server_type)) {
-      if (GetGroupForModelType(server_type, session->routing_info()) ==
-          session->status_controller().group_restriction()) {
-        server_type_restriction.set(server_type);
-      }
-    }
-  }
-
   syncable::Directory::UnappliedUpdateMetaHandles handles;
-  dir->GetUnappliedUpdateMetaHandles(
-      &trans, server_type_restriction, &handles);
+  dir->GetUnappliedUpdateMetaHandles(&trans, &handles);
 
   UpdateApplicator applicator(
       session->context()->resolver(),
@@ -89,6 +42,13 @@
   // some subset of the currently synced datatypes.
   const sessions::StatusController& status(session->status_controller());
   if (status.ServerSaysNothingMoreToDownload()) {
+    syncable::ScopedDirLookup dir(session->context()->directory_manager(),
+                                  session->context()->account_name());
+    if (!dir.good()) {
+      LOG(ERROR) << "Scoped dir lookup failed!";
+      return;
+    }
+
     for (int i = syncable::FIRST_REAL_MODEL_TYPE;
          i < syncable::MODEL_TYPE_COUNT; ++i) {
       syncable::ModelType model_type = syncable::ModelTypeFromInt(i);