sync: Make BaseNode lookup-related Init functions return specific failures.

chrome/browser/sync/test/integration/enable_disable_test.cc

Index: chrome/browser/sync/test/integration/enable_disable_test.cc
diff --git a/chrome/browser/sync/test/integration/enable_disable_test.cc b/chrome/browser/sync/test/integration/enable_disable_test.cc
index 100dea79e7b0d21ea76de30885dac2a7843f7182..29b6275140a5d4cc92b27df6a53674dfe68e438a 100644
--- a/chrome/browser/sync/test/integration/enable_disable_test.cc
+++ b/chrome/browser/sync/test/integration/enable_disable_test.cc
@@ -34,7 +34,8 @@ bool DoesTopLevelNodeExist(sync_api::UserShare* user_share,
                            syncable::ModelType type) {
     sync_api::ReadTransaction trans(FROM_HERE, user_share);
     sync_api::ReadNode node(&trans);
-    return node.InitByTagLookup(syncable::ModelTypeToRootTag(type));
+    return node.InitByTagLookup(syncable::ModelTypeToRootTag(type)) ==
+        sync_api::BaseNode::INIT_OK;
 }
 
 IN_PROC_BROWSER_TEST_F(EnableDisableSingleClientTest, EnableOneAtATime) {