IndexedDB: Rely on bindings for enum validation

Source/modules/indexeddb/IDBIndex.cpp

Index: Source/modules/indexeddb/IDBIndex.cpp
diff --git a/Source/modules/indexeddb/IDBIndex.cpp b/Source/modules/indexeddb/IDBIndex.cpp
index d0f335006326795fa582f735c8eb7d73d5d0272e..f3d31e7656922316aa306938e55245a077964e86 100644
--- a/Source/modules/indexeddb/IDBIndex.cpp
+++ b/Source/modules/indexeddb/IDBIndex.cpp
@@ -86,10 +86,7 @@ IDBRequest* IDBIndex::openCursor(ScriptState* scriptState, const ScriptValue& ra
         exceptionState.throwDOMException(TransactionInactiveError, IDBDatabase::transactionInactiveErrorMessage);
         return nullptr;
     }
-    WebIDBCursorDirection direction = IDBCursor::stringToDirection(directionString, exceptionState);
-    if (exceptionState.hadException())
-        return nullptr;
-
+    WebIDBCursorDirection direction = IDBCursor::stringToDirection(directionString);
     IDBKeyRange* keyRange = IDBKeyRange::fromScriptValue(scriptState->executionContext(), range, exceptionState);
     if (exceptionState.hadException())
         return nullptr;
@@ -155,10 +152,7 @@ IDBRequest* IDBIndex::openKeyCursor(ScriptState* scriptState, const ScriptValue&
         exceptionState.throwDOMException(TransactionInactiveError, IDBDatabase::transactionInactiveErrorMessage);
         return nullptr;
     }
-    WebIDBCursorDirection direction = IDBCursor::stringToDirection(directionString, exceptionState);
-    if (exceptionState.hadException())
-        return nullptr;
-
+    WebIDBCursorDirection direction = IDBCursor::stringToDirection(directionString);
     IDBKeyRange* keyRange = IDBKeyRange::fromScriptValue(scriptState->executionContext(), range, exceptionState);
     if (exceptionState.hadException())
         return nullptr;