IndexedDB: Make DOMException messages more useful.

Source/modules/indexeddb/IDBDatabase.h

Index: Source/modules/indexeddb/IDBDatabase.h
diff --git a/Source/modules/indexeddb/IDBDatabase.h b/Source/modules/indexeddb/IDBDatabase.h
index b68812421818712d8eaa87c6a952853b2b958f3a..67969dc136b852b6c48f555ec5f83a63e0d568a2 100644
--- a/Source/modules/indexeddb/IDBDatabase.h
+++ b/Source/modules/indexeddb/IDBDatabase.h
@@ -108,6 +108,18 @@ public:
     static int64_t nextTransactionId();
 
     static const char notFoundErrorMessage[];
+    static const char indexDeletedMessage[];
+    static const char isKeyCursorMessage[];
+    static const char noKeyOrKeyRangeMessage[];
+    static const char noSuchIndexMessage[];
+    static const char noSuchObjectStoreMessage[];
+    static const char notGotValueMessage[];
+    static const char notValidKeyMessage[];
+    static const char notVersionChangeTransactionMessage[];
+    static const char objectStoreDeletedMessage[];
+    static const char requestNotFinishedMessage[];
+    static const char sourceDeletedMessage[];
+    static const char transactionFinishedMessage[];
 
     using RefCounted<IDBDatabase>::ref;
     using RefCounted<IDBDatabase>::deref;