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

third_party/WebKit/Source/web/ExternalPopupMenu.cpp

 /*
  * 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 77 matching lines @@
         return false;
     WebLocalFrameImpl* webframe = WebLocalFrameImpl::fromFrame(m_localFrame.get());
     m_webExternalPopupMenu = webframe->client()->createExternalPopupMenu(info, this);
     if (m_webExternalPopupMenu) {
         LayoutObject* layoutObject = m_ownerElement->layoutObject();
         if (!layoutObject || !layoutObject->isBox())
             return false;
         FloatQuad quad(toLayoutBox(layoutObject)->localToAbsoluteQuad(FloatQuad(toLayoutBox(layoutObject)->borderBoundingBox())));
         IntRect rect(quad.enclosingBoundingBox());
         IntRect rectInViewport = m_localFrame->view()->soonToBeRemovedContentsToUnscaledViewport(rect);
-        // TODO(tkent): If the anchor rectangle is not visible, we should not
-        // show a popup.
         m_webExternalPopupMenu->show(rectInViewport);
-        m_shownDOMTreeVersion = m_ownerElement->document().domTreeVersion();
         return true;
     } else {
         // The client might refuse to create a popup (when there is already one pending to be shown for example).
         didCancel();
         return false;
     }
 }
 
 void ExternalPopupMenu::show()
 {
@@ skipping 23 matching lines @@
 void ExternalPopupMenu::hide()
 {
     if (m_ownerElement)
         m_ownerElement->popupDidHide();
     if (!m_webExternalPopupMenu)
         return;
     m_webExternalPopupMenu->close();
     m_webExternalPopupMenu = 0;
 }
 
-void ExternalPopupMenu::updateFromElement()
+void ExternalPopupMenu::updateFromElement(UpdateReason reason)
 {
-    if (m_needsUpdate)
-        return;
-    // TOOD(tkent): Even if DOMTreeVersion is not changed, we should update the
-    // popup location/content in some cases.  e.g. Updating ComputedStyle of the
-    // SELECT element affects popup position and OPTION style.
-    if (m_shownDOMTreeVersion == m_ownerElement->document().domTreeVersion())
-        return;
-    m_needsUpdate = true;
-    m_ownerElement->document().postTask(BLINK_FROM_HERE, createSameThreadTask(&ExternalPopupMenu::update, this));
+    switch (reason) {
+    case BySelectionChange:
+    case ByDOMChange:
+        if (m_needsUpdate)
+            return;
+        m_needsUpdate = true;
+        m_ownerElement->document().postTask(BLINK_FROM_HERE, createSameThreadTask(&ExternalPopupMenu::update, this));
+        break;
+
+    case ByStyleChange:
+        // TOOD(tkent): We should update the popup location/content in some
+        // cases.  e.g. Updating ComputedStyle of the SELECT element affects
+        // popup position and OPTION style.
+        break;
+    }
 }
 
 void ExternalPopupMenu::update()
 {
     if (!m_webExternalPopupMenu || !m_ownerElement)
         return;
     m_ownerElement->document().updateLayoutTree();
     // disconnectClient() might have been called.
     if (!m_ownerElement)
         return;
@@ skipping 124 matching lines @@
         if (ownerElement.itemIsDisplayNone(*items[i]))
             continue;
         if (popupMenuItemIndex == i)
             return indexTracker;
         ++indexTracker;
     }
     return -1;
 }
 
 } // namespace blink