Move isValid/isCurrentColor from Color to StyleColor

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 5b36f6d98dd9d80ddd218943526ac9224687e27b..64045a8e66be58df25890f97c753e3d345f469de 100644
--- a/Source/core/rendering/InlineTextBox.cpp
+++ b/Source/core/rendering/InlineTextBox.cpp
@@ -409,7 +409,8 @@ static void paintTextWithShadows(GraphicsContext* context,
             int shadowX = horizontal ? shadow->x() : shadow->y();
             int shadowY = horizontal ? shadow->y() : -shadow->x();
             FloatSize offset(shadowX, shadowY);
-            drawLooper.addShadow(offset, shadow->blur(), renderer->resolveColor(shadow->color()),
+            drawLooper.addShadow(offset, shadow->blur(),
+                renderer->resolveColor(shadow->color(), Color::stdShadowColor),
                 DrawLooper::ShadowRespectsTransforms, DrawLooper::ShadowIgnoresAlpha);
         } while ((shadow = shadow->next()));
         drawLooper.addUnmodifiedContent();
@@ -599,14 +600,14 @@ void InlineTextBox::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset,
     if (haveSelection) {
         // Check foreground color first.
         Color foreground = paintInfo.forceBlackText() ? Color::black : renderer()->selectionForegroundColor();
-        if (foreground.isValid() && foreground != selectionFillColor) {
+        if (foreground != Color::transparent && foreground != selectionFillColor) {
             if (!paintSelectedTextOnly)
                 paintSelectedTextSeparately = true;
             selectionFillColor = foreground;
         }
 
         Color emphasisMarkForeground = paintInfo.forceBlackText() ? Color::black : renderer()->selectionEmphasisMarkColor();
-        if (emphasisMarkForeground.isValid() && emphasisMarkForeground != selectionEmphasisMarkColor) {
+        if (emphasisMarkForeground != Color::transparent && emphasisMarkForeground != selectionEmphasisMarkColor) {
             if (!paintSelectedTextOnly)
                 paintSelectedTextSeparately = true;
             selectionEmphasisMarkColor = emphasisMarkForeground;
@@ -845,7 +846,7 @@ void InlineTextBox::paintSelection(GraphicsContext* context, const FloatPoint& b
         return;
 
     Color c = renderer()->selectionBackgroundColor();
-    if (!c.isValid() || c.alpha() == 0)
+    if (!c.alpha())
         return;
 
     // If the text color ends up being the same as the selection background, invert the selection
@@ -1139,7 +1140,8 @@ void InlineTextBox::paintDecoration(GraphicsContext* context, const FloatPoint&
             }
             int shadowX = isHorizontal() ? shadow->x() : shadow->y();
             int shadowY = isHorizontal() ? shadow->y() : -shadow->x();
-            context->setShadow(FloatSize(shadowX, shadowY - extraOffset), shadow->blur(), shadow->color());
+            context->setShadow(FloatSize(shadowX, shadowY - extraOffset), shadow->blur(),
+                renderer()->resolveColor(shadow->color(), Color::stdShadowColor));
             shadow = shadow->next();
         }