[Sync] Make GetFirstChildId return a flag indicating success

chrome/browser/sync/engine/process_commit_response_command_unittest.cc

Index: chrome/browser/sync/engine/process_commit_response_command_unittest.cc
diff --git a/chrome/browser/sync/engine/process_commit_response_command_unittest.cc b/chrome/browser/sync/engine/process_commit_response_command_unittest.cc
index 2f5846c4e74f6dd7ac4ac8edfd63d7ac905aa856..023a49f44cd8645327cfa10c3cc9d2f5f10c4a91 100644
--- a/chrome/browser/sync/engine/process_commit_response_command_unittest.cc
+++ b/chrome/browser/sync/engine/process_commit_response_command_unittest.cc
@@ -92,7 +92,9 @@ class ProcessCommitResponseCommandTestWithParam
     ScopedDirLookup dir(syncdb()->manager(), syncdb()->name());
     ASSERT_TRUE(dir.good());
     WriteTransaction trans(FROM_HERE, UNITTEST, dir);
-    Id predecessor_id = dir->GetLastChildId(&trans, parent_id);
+    Id predecessor_id;
+    ASSERT_TRUE(
+        dir->GetLastChildIdForTest(&trans, parent_id, &predecessor_id));
     MutableEntry entry(&trans, syncable::CREATE, parent_id, name);
     ASSERT_TRUE(entry.good());
     entry.Put(syncable::ID, item_id);
@@ -234,7 +236,8 @@ TEST_F(ProcessCommitResponseCommandTest, MultipleCommitIdProjections) {
   ScopedDirLookup dir(syncdb()->manager(), syncdb()->name());
   ASSERT_TRUE(dir.good());
   ReadTransaction trans(FROM_HERE, dir);
-  Id new_fid = dir->GetFirstChildId(&trans, id_factory_.root());
+  Id new_fid;
+  ASSERT_TRUE(dir->GetFirstChildId(&trans, id_factory_.root(), &new_fid));
   ASSERT_FALSE(new_fid.IsRoot());
   EXPECT_TRUE(new_fid.ServerKnows());
   EXPECT_FALSE(bookmark_folder_id.ServerKnows());
@@ -247,7 +250,8 @@ TEST_F(ProcessCommitResponseCommandTest, MultipleCommitIdProjections) {
       << "Bookmark folder should have a valid (positive) server base revision";
 
   // Look at the two bookmarks in bookmark_folder.
-  Id cid = dir->GetFirstChildId(&trans, new_fid);
+  Id cid;
+  ASSERT_TRUE(dir->GetFirstChildId(&trans, new_fid, &cid));
   Entry b1(&trans, syncable::GET_BY_ID, cid);
   Entry b2(&trans, syncable::GET_BY_ID, b1.Get(syncable::NEXT_ID));
   CheckEntry(&b1, "bookmark 1", syncable::BOOKMARKS, new_fid);
@@ -288,7 +292,9 @@ TEST_F(ProcessCommitResponseCommandTest, NewFolderCommitKeepsChildOrder) {
     ScopedDirLookup dir(syncdb()->manager(), syncdb()->name());
     ASSERT_TRUE(dir.good());
     ReadTransaction trans(FROM_HERE, dir);
-    ASSERT_EQ(folder_id, dir->GetFirstChildId(&trans, id_factory_.root()));
+    Id child_id;
+    ASSERT_TRUE(dir->GetFirstChildId(&trans, id_factory_.root(), &child_id));
+    ASSERT_EQ(folder_id, child_id);
   }
 
   // The first 25 children of the parent folder will be part of the commit
@@ -323,7 +329,8 @@ TEST_F(ProcessCommitResponseCommandTest, NewFolderCommitKeepsChildOrder) {
   ReadTransaction trans(FROM_HERE, dir);
   // Lookup the parent folder by finding a child of the root.  We can't use
   // folder_id here, because it changed during the commit.
-  Id new_fid = dir->GetFirstChildId(&trans, id_factory_.root());
+  Id new_fid;
+  ASSERT_TRUE(dir->GetFirstChildId(&trans, id_factory_.root(), &new_fid));
   ASSERT_FALSE(new_fid.IsRoot());
   EXPECT_TRUE(new_fid.ServerKnows());
   EXPECT_FALSE(folder_id.ServerKnows());
@@ -335,7 +342,8 @@ TEST_F(ProcessCommitResponseCommandTest, NewFolderCommitKeepsChildOrder) {
   ASSERT_LT(0, parent.Get(BASE_VERSION))
       << "Parent should have a valid (positive) server base revision";
 
-  Id cid = dir->GetFirstChildId(&trans, new_fid);
+  Id cid;
+  ASSERT_TRUE(dir->GetFirstChildId(&trans, new_fid, &cid));
   int child_count = 0;
   // Now loop over all the children of the parent folder, verifying
   // that they are in their original order by checking to see that their