Drop-down closes via tap/touch again.

third_party/WebKit/Source/web/WebViewImpl.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 649 matching lines @@
   // associated WM_CHAR event if the keydown was handled. We emulate
   // this behavior by setting this flag if the keyDown was handled.
   bool m_suppressNextKeypressEvent;
 
   // Represents whether or not this object should process incoming IME events.
   bool m_imeAcceptEvents;
 
   // The popup associated with an input/select element.
   RefPtr<WebPagePopupImpl> m_pagePopup;
 
+  // This stores the last hidden page popup. If a GestureTap attempts to open
+  // the popup that is closed by its previous GestureTapDown, the popup remains
+  // closed.
+  RefPtr<WebPagePopupImpl> m_lastHiddenPagePopup;
+
   Persistent<DevToolsEmulator> m_devToolsEmulator;
   std::unique_ptr<PageOverlay> m_pageColorOverlay;
 
   // Whether the webview is rendering transparently.
   bool m_isTransparent;
 
   // Whether the user can press tab to focus links.
   bool m_tabsToLinks;
 
   // If set, the (plugin) node which has mouse capture.
@@ skipping 53 matching lines @@
   Persistent<ResizeViewportAnchor> m_resizeViewportAnchor;
 };
 
 // We have no ways to check if the specified WebView is an instance of
 // WebViewImpl because WebViewImpl is the only implementation of WebView.
 DEFINE_TYPE_CASTS(WebViewImpl, WebView, webView, true, true);
 
 }  // namespace blink
 
 #endif