Remove SkiaFontWin as it is no longer used

Source/platform/fonts/harfbuzz/FontHarfBuzz.cpp

Index: Source/platform/fonts/harfbuzz/FontHarfBuzz.cpp
diff --git a/Source/platform/fonts/harfbuzz/FontHarfBuzz.cpp b/Source/platform/fonts/harfbuzz/FontHarfBuzz.cpp
index d21f7e9155210ce667e9c8827fd2ea7d749766b9..6bf4cb33b3364ea019e52992da05edbb405a282e 100644
--- a/Source/platform/fonts/harfbuzz/FontHarfBuzz.cpp
+++ b/Source/platform/fonts/harfbuzz/FontHarfBuzz.cpp
@@ -85,9 +85,15 @@ static void paintGlyphs(GraphicsContext* gc, const SimpleFontData* font,
         paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
 
         if (textMode & TextModeFill) {
-            // If we also filled, we don't want to draw shadows twice.
-            // See comment in FontChromiumWin.cpp::paintSkiaText() for more details.
-            // Since we use the looper for shadows, we remove it (if any) now.
+            // If there is a shadow and we filled above, there will already be
+            // a shadow. We don't want to draw it again or it will be too dark
+            // and it will go on top of the fill.
+            //
+            // Note that this isn't strictly correct, since the stroke could be
+            // very thick and the shadow wouldn't account for this. The "right"
+            // thing would be to draw to a new layer and then draw that layer
+            // with a shadow. But this is a lot of extra work for something
+            // that isn't normally an issue.
             paint.setLooper(0);
         }