pageshow event does not follow spec

Source/core/frame/DOMWindow.cpp

Index: Source/core/frame/DOMWindow.cpp
diff --git a/Source/core/frame/DOMWindow.cpp b/Source/core/frame/DOMWindow.cpp
index 9d85771d908ce7868b7e3d666b68851fcef5a44d..6993a7d53063835a44da5ee9cbff1365f11d7a9c 100644
--- a/Source/core/frame/DOMWindow.cpp
+++ b/Source/core/frame/DOMWindow.cpp
@@ -454,6 +454,8 @@ void DOMWindow::documentWasClosed()
 void DOMWindow::enqueuePageshowEvent(PageshowEventPersistence persisted)
 {
     // FIXME: https://bugs.webkit.org/show_bug.cgi?id=36334 Pageshow event needs to fire asynchronously.
+    // As per spec pageshow must be triggered asynchronously.
+    // However to be compatible with other browsers blink fires pageshow synchronously.
     dispatchEvent(PageTransitionEvent::create(EventTypeNames::pageshow, persisted), m_document.get());
 }