calc expressions should support time, angle and frequency values.

Source/core/css/CSSPrimitiveValue.h

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 255 matching lines @@
         return adoptRefWillBeNoop(quirkValue);
     }
 
     ~CSSPrimitiveValue();
 
     void cleanup();
 
     UnitType primitiveType() const;
 
     double computeDegrees();
-
-    enum TimeUnit { Seconds, Milliseconds };
-    template <typename T, TimeUnit timeUnit> T computeTime()
-    {
-        if (timeUnit == Seconds && m_primitiveUnitType == CSS_S)
-            return getValue<T>();
-        if (timeUnit == Seconds && m_primitiveUnitType == CSS_MS)
-            return getValue<T>() / 1000;
-        if (timeUnit == Milliseconds && m_primitiveUnitType == CSS_MS)
-            return getValue<T>();
-        if (timeUnit == Milliseconds && m_primitiveUnitType == CSS_S)
-            return getValue<T>() * 1000;
-        ASSERT_NOT_REACHED();
-        return 0;
-    }
+    double computeSeconds();
 
     /*
      * Computes a length in pixels out of the given CSSValue
      *
      * The metrics have to be a bit different for screen and printer output.
      * For screen output we assume 1 inch == 72 px, for printer we assume 300 dpi
      *
      * this is screen/printer dependent, so we probably need a config option for this,
      * and some tool to calibrate.
      */
@@ skipping 124 matching lines @@
     } m_value;
 };
 
 typedef CSSPrimitiveValue::CSSLengthArray CSSLengthArray;
 
 DEFINE_CSS_VALUE_TYPE_CASTS(CSSPrimitiveValue, isPrimitiveValue());
 
 } // namespace blink
 
 #endif // CSSPrimitiveValue_h