calc expressions should support time, angle and frequency values.

Source/core/css/CSSPrimitiveValue.h

Index: Source/core/css/CSSPrimitiveValue.h
diff --git a/Source/core/css/CSSPrimitiveValue.h b/Source/core/css/CSSPrimitiveValue.h
index 80f492a810fb32225bd691574c2a4551373ff33e..642d400c1a4bbdcdb0c3bdd63b4a1fd0805d2ee3 100644
--- a/Source/core/css/CSSPrimitiveValue.h
+++ b/Source/core/css/CSSPrimitiveValue.h
@@ -273,21 +273,7 @@ public:
     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