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

content/browser/indexed_db/indexed_db_database.h

Index: content/browser/indexed_db/indexed_db_database.h
diff --git a/content/browser/indexed_db/indexed_db_database.h b/content/browser/indexed_db/indexed_db_database.h
index a6e30f366a74162594d23af0e5e05f095d8c4ba9..c0bd78931764da09d9d1106fb1322091f06d448c 100644
--- a/content/browser/indexed_db/indexed_db_database.h
+++ b/content/browser/indexed_db/indexed_db_database.h
@@ -175,13 +175,10 @@ class CONTENT_EXPORT IndexedDBDatabase
   size_t PendingDeleteCount() const;
 
   // Asynchronous tasks scheduled within transactions:
-  void CreateObjectStoreOperation(
-      const IndexedDBObjectStoreMetadata& object_store_metadata,
-      IndexedDBTransaction* transaction);
   void CreateObjectStoreAbortOperation(int64 object_store_id,
                                        IndexedDBTransaction* transaction);
   void DeleteObjectStoreOperation(
-      const IndexedDBObjectStoreMetadata& object_store_metadata,
+      int64 object_store_id,

[jsbell, 2014/05/19 22:07:08]

Metadata should be snapshotted asynchronously, so ID is sufficient here.

c/o a race found by running transaction-basics.html a 2500 times; would DCHECK
fail about 0.5% of the time. The failure case was 
deleteIndex/deleteObjectStore/abort - the abort would first restore the
objectStore but with metadata including the index, and second restoring the
index - *boom*.

       IndexedDBTransaction* transaction);
   void DeleteObjectStoreAbortOperation(
       const IndexedDBObjectStoreMetadata& object_store_metadata,
@@ -193,11 +190,8 @@ class CONTENT_EXPORT IndexedDBDatabase
   void VersionChangeAbortOperation(const base::string16& previous_version,
                                    int64 previous_int_version,
                                    IndexedDBTransaction* transaction);
-  void CreateIndexOperation(int64 object_store_id,
-                            const IndexedDBIndexMetadata& index_metadata,
-                            IndexedDBTransaction* transaction);
   void DeleteIndexOperation(int64 object_store_id,
-                            const IndexedDBIndexMetadata& index_metadata,
+                            int64 index_id,

[jsbell, 2014/05/19 22:07:08]

Metadata should be snapshotted asynchronously, so ID is sufficient here.

                             IndexedDBTransaction* transaction);
   void CreateIndexAbortOperation(int64 object_store_id,
                                  int64 index_id,