Align IndexedDB metadata rollback on transaction abort to spec.

third_party/WebKit/Source/modules/indexeddb/IDBObjectStore.h

Index: third_party/WebKit/Source/modules/indexeddb/IDBObjectStore.h
diff --git a/third_party/WebKit/Source/modules/indexeddb/IDBObjectStore.h b/third_party/WebKit/Source/modules/indexeddb/IDBObjectStore.h
index 9349f10380237c95024c5baf0788d9d093d8318c..3d4baf184326b0f3b3981e46276debf2ab262ff0 100644
--- a/third_party/WebKit/Source/modules/indexeddb/IDBObjectStore.h
+++ b/third_party/WebKit/Source/modules/indexeddb/IDBObjectStore.h
@@ -39,7 +39,6 @@
 #include "public/platform/modules/indexeddb/WebIDBCursor.h"
 #include "public/platform/modules/indexeddb/WebIDBDatabase.h"
 #include "public/platform/modules/indexeddb/WebIDBTypes.h"
-#include "wtf/PassRefPtr.h"
 #include "wtf/RefPtr.h"
 #include "wtf/text/WTFString.h"
 
@@ -52,21 +51,23 @@ class ExceptionState;
 class IDBObjectStore final : public GarbageCollectedFinalized<IDBObjectStore>, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
-    static IDBObjectStore* create(const IDBObjectStoreMetadata& metadata, IDBTransaction* transaction)
+    static IDBObjectStore* create(RefPtr<IDBObjectStoreMetadata> metadata, IDBTransaction* transaction)
     {
-        return new IDBObjectStore(metadata, transaction);
+        return new IDBObjectStore(std::move(metadata), transaction);
     }
     ~IDBObjectStore() { }
     DECLARE_TRACE();
 
+    const IDBObjectStoreMetadata& metadata() const { return *m_metadata; }
+
     // Implement the IDBObjectStore IDL
-    int64_t id() const { return m_metadata.id; }
-    const String& name() const { return m_metadata.name; }
+    int64_t id() const { return metadata().own.id; }
+    const String& name() const { return metadata().own.name; }
     void setName(const String& name, ExceptionState&);
     ScriptValue keyPath(ScriptState*) const;
     DOMStringList* indexNames() const;
     IDBTransaction* transaction() const { return m_transaction.get(); }
-    bool autoIncrement() const { return m_metadata.autoIncrement; }
+    bool autoIncrement() const { return metadata().own.autoIncrement; }
 
     IDBRequest* openCursor(ScriptState*, const ScriptValue& range, const String& direction, ExceptionState&);
     IDBRequest* openKeyCursor(ScriptState*, const ScriptValue& range, const String& direction, ExceptionState&);
@@ -96,43 +97,55 @@ public:
     // Used internally and by InspectorIndexedDBAgent:
     IDBRequest* openCursor(ScriptState*, IDBKeyRange*, WebIDBCursorDirection, WebIDBTaskType = WebIDBTaskTypeNormal);
 
-    void markDeleted() { m_deleted = true; }
+    void markDeleted();
     bool isDeleted() const { return m_deleted; }
-    void abort();
     void transactionFinished();
 
-    const IDBObjectStoreMetadata& metadata() const { return m_metadata; }
-    void setMetadata(const IDBObjectStoreMetadata& metadata) { m_metadata = metadata; }
-
-    typedef HeapVector<Member<IDBKey>> IndexKeys;
+    // Sets the object store's metadata to a previous version.
+    //
+    // The reverting process includes reverting the metadata for the IDBIndex
+    // instances that are still tracked by the store. It does not revert the
+    // IDBIndex metadata for indexes that were deleted in this transaction.
+    //
+    // Used when a versionchange transaction is aborted.
+    void revertMetadata(RefPtr<IDBObjectStoreMetadata> previousMetadata);
+    // This relies on the changes made by revertMetadata().
+    void revertDeletedIndexMetadata(IDBIndex& deletedIndex);
 
     // Used by IDBIndex::setName:
     bool containsIndex(const String& name) const
     {
         return findIndexId(name) != IDBIndexMetadata::InvalidId;
     }
-    void indexRenamed(int64_t indexId, const String& newName);
+    void renameIndex(int64_t indexId, const String& newName);
 
     WebIDBDatabase* backendDB() const;
 
 private:
-    IDBObjectStore(const IDBObjectStoreMetadata&, IDBTransaction*);
+    IDBObjectStore(RefPtr<IDBObjectStoreMetadata>, IDBTransaction*);
 
     IDBIndex* createIndex(ScriptState*, const String& name, const IDBKeyPath&, const IDBIndexParameters&, ExceptionState&);
     IDBRequest* put(ScriptState*, WebIDBPutMode, IDBAny* source, const ScriptValue&, const ScriptValue& key, ExceptionState&);
 
     int64_t findIndexId(const String& name) const;
 
-    IDBObjectStoreMetadata m_metadata;
+    // The IDBObjectStoreMetadata is shared with the object store map in the
+    // database's metadata.
+    RefPtr<IDBObjectStoreMetadata> m_metadata;
     Member<IDBTransaction> m_transaction;
     bool m_deleted = false;
 
-    typedef HeapHashMap<String, Member<IDBIndex>> IDBIndexMap;
-    IDBIndexMap m_indexMap;
-
-    // Used to mark indexes created in an aborted upgrade transaction as
-    // deleted.
-    HeapHashSet<Member<IDBIndex>> m_createdIndexes;
+    // Caches the IDBIndex instances returned by the index() method.
+    //
+    // The spec requires that an object store's index() returns the same
+    // IDBIndex instance for a specific index, so this cache is necessary
+    // for correctness.
+    //
+    // The cache may be in an inconsistent state after a transaction is aborted.
+    // index() throws for inactive transactions, which makes the cache not
+    // observable, so reverting the cache would be a waste of resources.
+    using IndexMap = HeapHashMap<String, Member<IDBIndex>>;
+    IndexMap m_indexMap;
 };
 
 } // namespace blink