Replace compile flag with runtime check for text-underline-position

Source/core/rendering/InlineTextBox.cpp

Index: Source/core/rendering/InlineTextBox.cpp
diff --git a/Source/core/rendering/InlineTextBox.cpp b/Source/core/rendering/InlineTextBox.cpp
index c5eff52094f0522dfb3d31262b97788995e9e592..3f615732900dff3448eeb6d08faf9dca38c0fb1e 100644
--- a/Source/core/rendering/InlineTextBox.cpp
+++ b/Source/core/rendering/InlineTextBox.cpp
@@ -916,8 +916,7 @@ static StrokeStyle textDecorationStyleToStrokeStyle(TextDecorationStyle decorati
     return strokeStyle;
 }
 
-#if ENABLE(CSS3_TEXT)
-static int computeUnderlineOffset(const TextUnderlinePosition underlinePosition, const FontMetrics& fontMetrics, const InlineTextBox* inlineTextBox, const int textDecorationThickness)
+static int computeUnderlineOffset(const TextUnderlinePosition underlinePosition, const FontMetrics& fontMetrics, const InlineTextBox* inlineTextBox, const float textDecorationThickness)
 {
     // Compute the gap between the font and the underline. Use at least one
     // pixel gap, if underline is thick then use a bigger gap.
@@ -941,7 +940,6 @@ static int computeUnderlineOffset(const TextUnderlinePosition underlinePosition,
     ASSERT_NOT_REACHED();
     return fontMetrics.ascent() + gap;
 }
-#endif // CSS3_TEXT
 
 static void adjustStepToDecorationLength(float& step, float& controlPointDistance, float length)
 {
@@ -1140,13 +1138,7 @@ void InlineTextBox::paintDecoration(GraphicsContext* context, const FloatPoint&
         context->setStrokeStyle(textDecorationStyleToStrokeStyle(decorationStyle));
         if (deco & TextDecorationUnderline) {
             context->setStrokeColor(underline);
-#if ENABLE(CSS3_TEXT)
-            TextUnderlinePosition underlinePosition = styleToUse->textUnderlinePosition();
-            const int underlineOffset = computeUnderlineOffset(underlinePosition, styleToUse->fontMetrics(), this, textDecorationThickness);
-#else
-            const int underlineOffset = styleToUse->fontMetrics().ascent() + max<int>(1, ceilf(textDecorationThickness / 2.0));
-#endif // CSS3_TEXT
-
+            const int underlineOffset = computeUnderlineOffset(styleToUse->textUnderlinePosition(), styleToUse->fontMetrics(), this, textDecorationThickness);
             switch (decorationStyle) {
             case TextDecorationStyleWavy: {
                 FloatPoint start(localOrigin.x(), localOrigin.y() + underlineOffset + doubleOffset);