[Sync] Make GetFirstChildId return a flag indicating success

chrome/browser/sync/internal_api/sync_manager.cc

 // Copyright (c) 2011 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 "chrome/browser/sync/internal_api/sync_manager.h"
 
 #include <string>
 
 #include "base/base64.h"
 #include "base/command_line.h"
@@ skipping 1383 matching lines @@
   // underlying transaction.
   ReadTransaction read_trans(GetUserShare(), trans);
 
   syncable::ModelTypeBitSet models_with_changes;
   for (int i = syncable::FIRST_REAL_MODEL_TYPE;
        i < syncable::MODEL_TYPE_COUNT; ++i) {
     const syncable::ModelType type = syncable::ModelTypeFromInt(i);
     if (change_buffers_[type].IsEmpty())
       continue;
 
-    ImmutableChangeRecordList ordered_changes =
-        change_buffers_[type].GetAllChangesInTreeOrder(&read_trans);
+    ImmutableChangeRecordList ordered_changes;
+    // TODO(akalin): Propagate up the error further (see
+    // http://crbug.com/100907).
+    CHECK(change_buffers_[type].GetAllChangesInTreeOrder(&read_trans,
+                                                         &ordered_changes));
     if (!ordered_changes.Get().empty()) {
       change_delegate_->
           OnChangesApplied(type, &read_trans, ordered_changes);
       change_observers_->Notify(
           &SyncManager::ChangeObserver::OnChangesApplied,
           type, write_transaction_info.Get().id, ordered_changes);
       models_with_changes.set(i, true);
     }
     change_buffers_[i].Clear();
   }
@@ skipping 657 matching lines @@
 
   for (syncable::ModelTypeSet::const_iterator i = types.begin();
        i != types.end(); ++i) {
     if (!lookup->initial_sync_ended_for_type(*i))
       return false;
   }
   return true;
 }
 
 }  // namespace sync_api