Optimizes the operation of DeleteDatabase when no backing store exists.

content/browser/indexed_db/indexed_db_browsertest.cc

Index: content/browser/indexed_db/indexed_db_browsertest.cc
diff --git a/content/browser/indexed_db/indexed_db_browsertest.cc b/content/browser/indexed_db/indexed_db_browsertest.cc
index 21f6ad671169d1a724f4d752361451104f6c2528..4e659bc51217b0f29d320d7843a209a2f1171eba 100644
--- a/content/browser/indexed_db/indexed_db_browsertest.cc
+++ b/content/browser/indexed_db/indexed_db_browsertest.cc
@@ -507,7 +507,7 @@ IN_PROC_BROWSER_TEST_F(IndexedDBBrowserTest, DiskFullOnCommit) {
   //   #6: IndexedDBTransaction::Commit - initial "versionchange" transaction
   // * Once the connection is opened, the test runs:
   //   #7: IndexedDBTransaction::Commit - the test's "readwrite" transaction)
-  const int instance_num = 7;
+  const int instance_num = 5;
   const int call_num = 1;
   FailOperation(FAIL_CLASS_LEVELDB_TRANSACTION, FAIL_METHOD_COMMIT_DISK_FULL,
                 instance_num, call_num);