ExternalPopupMenu should recreate its popup only if a SELECT subtree is updated

third_party/WebKit/Source/web/ExternalPopupMenu.h

Index: third_party/WebKit/Source/web/ExternalPopupMenu.h
diff --git a/third_party/WebKit/Source/web/ExternalPopupMenu.h b/third_party/WebKit/Source/web/ExternalPopupMenu.h
index a637cf7bcb3ef7abf7b81cce07e01c724a43cda8..e11ef4b9308408c2ccbf2afd523505d3739eb0ec 100644
--- a/third_party/WebKit/Source/web/ExternalPopupMenu.h
+++ b/third_party/WebKit/Source/web/ExternalPopupMenu.h
@@ -69,7 +69,7 @@ private:
     // PopupMenu methods:
     void show() override;
     void hide() override;
-    void updateFromElement() override;
+    void updateFromElement(UpdateReason) override;
     void disconnectClient() override;
 
     // WebExternalPopupClient methods:
@@ -89,7 +89,6 @@ private:
     Timer<ExternalPopupMenu> m_dispatchEventTimer;
     // The actual implementor of the show menu.
     WebExternalPopupMenu* m_webExternalPopupMenu;
-    uint64_t m_shownDOMTreeVersion = 0;
     bool m_needsUpdate = false;
 };