IndexedDB: Prevent store/index deletion from racing ahead of use

content/browser/indexed_db/indexed_db_fake_backing_store.cc

Index: content/browser/indexed_db/indexed_db_fake_backing_store.cc
diff --git a/content/browser/indexed_db/indexed_db_fake_backing_store.cc b/content/browser/indexed_db/indexed_db_fake_backing_store.cc
index 35e3a50e4d82e52eb534d0549810c2ad265ae498..08e558f794a765384cfb48deb3f630a4f625804e 100644
--- a/content/browser/indexed_db/indexed_db_fake_backing_store.cc
+++ b/content/browser/indexed_db/indexed_db_fake_backing_store.cc
@@ -67,21 +67,21 @@ leveldb::Status IndexedDBFakeBackingStore::CreateObjectStore(
     const base::string16& name,
     const IndexedDBKeyPath&,
     bool auto_increment) {
-  return leveldb::Status::IOError("test error");
+  return leveldb::Status::OK();
 }
 
 leveldb::Status IndexedDBFakeBackingStore::ClearObjectStore(
     Transaction*,
     int64 database_id,
     int64 object_store_id) {
-  return leveldb::Status::IOError("test error");
+  return leveldb::Status::OK();
 }
 leveldb::Status IndexedDBFakeBackingStore::DeleteRecord(
     Transaction*,
     int64 database_id,
     int64 object_store_id,
     const RecordIdentifier&) {
-  return leveldb::Status::IOError("test error");
+  return leveldb::Status::OK();
 }
 leveldb::Status IndexedDBFakeBackingStore::GetKeyGeneratorCurrentNumber(
     Transaction*,
@@ -117,14 +117,14 @@ leveldb::Status IndexedDBFakeBackingStore::CreateIndex(
     const IndexedDBKeyPath&,
     bool is_unique,
     bool is_multi_entry) {
-  return leveldb::Status::IOError("test error");
+  return leveldb::Status::OK();
 }
 
 leveldb::Status IndexedDBFakeBackingStore::DeleteIndex(Transaction*,
                                                        int64 database_id,
                                                        int64 object_store_id,
                                                        int64 index_id) {
-  return leveldb::Status::IOError("test error");
+  return leveldb::Status::OK();
 }
 leveldb::Status IndexedDBFakeBackingStore::PutIndexDataForRecord(
     Transaction*,
@@ -133,7 +133,7 @@ leveldb::Status IndexedDBFakeBackingStore::PutIndexDataForRecord(
     int64 index_id,
     const IndexedDBKey&,
     const RecordIdentifier&) {
-  return leveldb::Status::IOError("test error");
+  return leveldb::Status::OK();
 }
 
 void IndexedDBFakeBackingStore::ReportBlobUnused(int64 database_id,