Implement support to consider <space> key as part of typeAhead searching.

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 1207 matching lines @@
     return ((layoutTheme.popsMenuByArrowKeys() &&  (keyIdentifier == "Down" || keyIdentifier == "Up"))
         || (layoutTheme.popsMenuByAltDownUpOrF4Key() && (keyIdentifier == "Down" || keyIdentifier == "Up") && keyEvent->altKey())
         || (layoutTheme.popsMenuByAltDownUpOrF4Key() && (!keyEvent->altKey() && !keyEvent->ctrlKey() && keyIdentifier == "F4")));
 }
 
 bool HTMLSelectElement::shouldOpenPopupForKeyPressEvent(KeyboardEvent *event)
 {
     LayoutTheme& layoutTheme = LayoutTheme::theme();
     int keyCode = event->keyCode();
 
-    return ((layoutTheme.popsMenuBySpaceKey() && event->keyCode() == ' ')
+    return ((layoutTheme.popsMenuBySpaceKey() && event->keyCode() == ' ' && !m_typeAhead.hasActiveSession(event))
         || (layoutTheme.popsMenuByReturnKey() && keyCode == '\r'));
 }
 
 void HTMLSelectElement::menuListDefaultEventHandler(Event* event)
 {
     if (event->type() == EventTypeNames::keydown) {
         if (!layoutObject() || !event->isKeyboardEvent())
             return;
 
         KeyboardEvent* keyEvent = toKeyboardEvent(event);
@@ skipping 529 matching lines @@
     int focusedIndex = activeSelectionEndListIndex();
     if (focusedIndex < 0)
         focusedIndex = firstSelectableListIndex();
     if (focusedIndex < 0)
         return nullptr;
     HTMLElement* focused = listItems()[focusedIndex];
     return isHTMLOptionElement(focused) ? toHTMLOptionElement(focused) : nullptr;
 }
 
 } // namespace