Remove ACCELERATED_OVERFLOW_SCROLLING as it is always off.

Source/core/css/resolver/StyleResolver.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 1576 matching lines @@
     if (style->hasAutoZIndex() && ((e && e->document()->documentElement() == e)
         || style->opacity() < 1.0f
         || style->hasTransformRelatedProperty()
         || style->hasMask()
         || style->clipPath()
         || style->boxReflect()
         || style->hasFilter()
         || style->hasBlendMode()
         || style->position() == StickyPosition
         || (style->position() == FixedPosition && e && e->document()->page() && e->document()->page()->settings()->fixedPositionCreatesStackingContext())
-#if ENABLE(ACCELERATED_OVERFLOW_SCROLLING)
-        // Touch overflow scrolling creates a stacking context.
-        || ((style->overflowX() != OHIDDEN || style->overflowY() != OHIDDEN) && style->useTouchOverflowScrolling())
-#endif
         || (e && e->isInTopLayer())
         ))
         style->setZIndex(0);
 
     // Textarea considers overflow visible as auto.
     if (e && e->hasTagName(textareaTag)) {
         style->setOverflowX(style->overflowX() == OVISIBLE ? OAUTO : style->overflowX());
         style->setOverflowY(style->overflowY() == OVISIBLE ? OAUTO : style->overflowY());
     }
 
@@ skipping 1226 matching lines @@
     }
     case CSSPropertyWebkitTapHighlightColor: {
         HANDLE_INHERIT_AND_INITIAL(tapHighlightColor, TapHighlightColor);
         if (!primitiveValue)
             break;
 
         Color col = m_state.colorFromPrimitiveValue(primitiveValue);
         state.style()->setTapHighlightColor(col);
         return;
     }
-#if ENABLE(ACCELERATED_OVERFLOW_SCROLLING)
-    case CSSPropertyWebkitOverflowScrolling: {
-        HANDLE_INHERIT_AND_INITIAL(useTouchOverflowScrolling, UseTouchOverflowScrolling);
-        if (!primitiveValue)
-            break;
-        state.style()->setUseTouchOverflowScrolling(primitiveValue->getValueID() == CSSValueTouch);
-        return;
-    }
-#endif
     case CSSPropertyInvalid:
         return;
     // Directional properties are resolved by resolveDirectionAwareProperty() before the switch.
     case CSSPropertyWebkitBorderEndColor:
     case CSSPropertyWebkitBorderEndStyle:
     case CSSPropertyWebkitBorderEndWidth:
     case CSSPropertyWebkitBorderStartColor:
     case CSSPropertyWebkitBorderStartStyle:
     case CSSPropertyWebkitBorderStartWidth:
     case CSSPropertyWebkitBorderBeforeColor:
@@ skipping 865 matching lines @@
     info.addMember(m_state, "state");
 
     // FIXME: move this to a place where it would be called only once?
     info.addMember(CSSDefaultStyleSheets::defaultStyle, "defaultStyle");
     info.addMember(CSSDefaultStyleSheets::defaultQuirksStyle, "defaultQuirksStyle");
     info.addMember(CSSDefaultStyleSheets::defaultPrintStyle, "defaultPrintStyle");
     info.addMember(CSSDefaultStyleSheets::defaultViewSourceStyle, "defaultViewSourceStyle");
 }
 
 } // namespace WebCore