Do not open SELECT popup if the SELECT element is not in the viewport.

third_party/WebKit/Source/core/html/HTMLSelectElement.cpp

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
@@ skipping 1858 matching lines @@
 
 const ComputedStyle* HTMLSelectElement::itemComputedStyle(Element& element) const
 {
     return element.computedStyle() ? element.computedStyle() : element.ensureComputedStyle();
 }
 
 IntRect HTMLSelectElement::elementRectRelativeToViewport() const
 {
     if (!layoutObject())
         return IntRect();
+    // Initialize with this frame rectangle relative to the viewport.
+    IntRect rect = document().view()->convertToRootFrame(document().view()->boundsRect());
     // We don't use absoluteBoundingBoxRect() because it can return an IntRect
     // larger the actual size by 1px.
-    return document().view()->contentsToViewport(roundedIntRect(layoutObject()->absoluteBoundingBoxFloatRect()));
+    rect.intersect(document().view()->contentsToViewport(roundedIntRect(layoutObject()->absoluteBoundingBoxFloatRect())));
+    return rect;
 }
 
 LayoutUnit HTMLSelectElement::clientPaddingLeft() const
 {
     if (layoutObject() && layoutObject()->isMenuList())
         return toLayoutMenuList(layoutObject())->clientPaddingLeft();
     return LayoutUnit();
 }
 
 LayoutUnit HTMLSelectElement::clientPaddingRight() const
@@ skipping 52 matching lines @@
 }
 
 void HTMLSelectElement::showPopup()
 {
     if (popupIsVisible())
         return;
     if (document().frameHost()->chromeClient().hasOpenedPopup())
         return;
     if (!layoutObject() || !layoutObject()->isMenuList())
         return;
+    if (elementRectRelativeToViewport().isEmpty())
+        return;
 
     if (!m_popup)
         m_popup = document().frameHost()->chromeClient().openPopupMenu(*document().frame(), *this);
     m_popupIsVisible = true;
 
     LayoutMenuList* menuList = toLayoutMenuList(layoutObject());
     m_popup->show();
     if (AXObjectCache* cache = document().existingAXObjectCache())
         cache->didShowMenuListPopup(menuList);
 }
@@ skipping 19 matching lines @@
     m_popupIsVisible = false;
     m_popup = nullptr;
 }
 
 void HTMLSelectElement::resetTypeAheadSessionForTesting()
 {
     m_typeAhead.resetSession();
 }
 
 } // namespace blink