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

Source/core/css/CSSPrimitiveValueMappings.h

 /*
  * Copyright (C) 2007 Alexey Proskuryakov <ap@nypop.com>.
  * Copyright (C) 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2009 Jeff Schiller <codedread@gmail.com>
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ skipping 4854 matching lines @@
     : CSSValue(PrimitiveClass)
 {
     m_primitiveUnitType = CSS_VALUE_ID;
     switch (t) {
     case TouchActionNone:
         m_value.valueID = CSSValueNone;
         break;
     case TouchActionAuto:
         m_value.valueID = CSSValueAuto;
         break;
+    case TouchActionPanX:

[Rick Byers, 2013/12/06 21:44:04]

I think these two functions should go away.  They treat TouchAction as a
primitive value, but it's now a set of flags and so the TouchAction to CSSValue
mapping is more complex.

Instead you should update
StyleBuilderFunctions::applyValueCSSPropertyTouchAction to know the mapping (and
you already have the other direction in touchActionFlagsToCSSValue).

[gnana, 2013/12/10 18:24:37]

Removing this two function caused build error. Working on it.
Will update in next patch.

[Rick Byers, 2013/12/10 21:57:14]

Ok.  It's possible I'm missing something here - let me know if there's something
that depends on this that's not trivial to remove.  Naively it seems that
anything that depends on this would be broken in flag combination cases like
'pan-x pan-y'

[gnana, 2013/12/11 14:02:53]

Done.
I removed one function. But cannot remove the operator TouchAction()
Because in StyleBuilderFunctions::applyValueCSSPropertyTouchAction the arguement
is a cssvaluelist of primitive values. hence we need this function.

[Rick Byers, 2013/12/12 15:30:35]

Yeah, I was thinking you'd want to essentially inline this logic into
applyValueCSSPropertyTouchAction.  But that's fine - there's nothing lossy with
going that direction, and I see it's consistent with how TextDecoration (also a
set of flags) works.  Thanks.

+        m_value.valueID = CSSValuePanX;
+        break;
+    case TouchActionPanY:
+        m_value.valueID = CSSValuePanY;
+        break;
     }
 }
 
 template<> inline CSSPrimitiveValue::operator TouchAction() const
 {
     ASSERT(isValueID());
     switch (m_value.valueID) {
     case CSSValueNone:
         return TouchActionNone;
     case CSSValueAuto:
         return TouchActionAuto;
+    case CSSValuePanX:
+        return TouchActionPanX;
+    case CSSValuePanY:
+        return TouchActionPanY;
     default:
         break;
     }
 
     ASSERT_NOT_REACHED();
     return TouchActionNone;
 }
 
 template<> inline CSSPrimitiveValue::CSSPrimitiveValue(EIsolation i)
     : CSSValue(PrimitiveClass)
@@ skipping 88 matching lines @@
     default:
         break;
     }
     ASSERT_NOT_REACHED();
     return ContentBox;
 }
 
 }
 
 #endif