IndexedDB: Align abort behavior on uncaught exception with Gecko

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

Index: third_party/WebKit/Source/modules/indexeddb/IDBRequest.h
diff --git a/third_party/WebKit/Source/modules/indexeddb/IDBRequest.h b/third_party/WebKit/Source/modules/indexeddb/IDBRequest.h
index 94300e9ee398e58a051bb65f61e3cb15d8005b17..41ca61fb26402fd9c2f5c378331c186892bffd47 100644
--- a/third_party/WebKit/Source/modules/indexeddb/IDBRequest.h
+++ b/third_party/WebKit/Source/modules/indexeddb/IDBRequest.h
@@ -191,6 +191,12 @@ class MODULES_EXPORT IDBRequest : public EventTargetWithInlineData,
   bool m_preventPropagation = false;
   bool m_resultDirty = true;
 
+  // Transactions should be aborted after event dispatch if an exception was
+  // not caught. This is cleared before dispatch, set by a call to
+  // uncaughtExceptionInEventHandler() during dispatch, and checked afterwards
+  // to abort if necessary.
+  bool m_didThrowInEventHandler = false;
+
   // Pointer back to the WebIDBCallbacks that holds a persistent reference to
   // this object.
   WebIDBCallbacks* m_webCallbacks = nullptr;