add pan-x and pan-y support to CSS touch-action parsing.

Source/core/rendering/style/RenderStyleConstants.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 496 matching lines @@
 enum WrapFlow { WrapFlowAuto, WrapFlowBoth, WrapFlowStart, WrapFlowEnd, WrapFlowMaximum, WrapFlowClear };
 
 enum WrapThrough { WrapThroughWrap, WrapThroughNone };
 
 enum RubyPosition { RubyPositionBefore, RubyPositionAfter };
 
 enum GridAutoFlow { AutoFlowNone, AutoFlowColumn, AutoFlowRow };
 
 enum DraggableRegionMode { DraggableRegionNone, DraggableRegionDrag, DraggableRegionNoDrag };
 
-enum TouchAction { TouchActionAuto, TouchActionNone };
+enum TouchAction {
+    TouchActionAuto = 0x0,
+    TouchActionNone =  0x1,
+    TouchActionPanX = 0x2,
+    TouchActionPanY = 0x4
+};
+inline TouchAction operator| (TouchAction a, TouchAction b) { return TouchAction(int(a) | int(b)); }
+inline TouchAction& operator|= (TouchAction& a, TouchAction b) { return a = a | b; }
 
 enum EIsolation { IsolationAuto, IsolationIsolate };
 
 enum TouchActionDelay { TouchActionDelayNone, TouchActionDelayScript };
 
 // Reasonable maximum to prevent insane font sizes from causing crashes on some platforms (such as Windows).
 static const float maximumAllowedFontSize = 1000000.0f;
 
 enum TextIndentLine { TextIndentFirstLine, TextIndentEachLine };
 
 enum LayoutBox { MarginBox, BorderBox, PaddingBox, ContentBox };
 
 } // namespace WebCore
 
 #endif // RenderStyleConstants_h