Remove an unused function.

src/ports/SkFontHost_win.cpp

Index: src/ports/SkFontHost_win.cpp
diff --git a/src/ports/SkFontHost_win.cpp b/src/ports/SkFontHost_win.cpp
index 953a9e457243f2be4755b64476d30c0606962f52..e45a48537226836032488fabc430b587e8692390 100755
--- a/src/ports/SkFontHost_win.cpp
+++ b/src/ports/SkFontHost_win.cpp
@@ -1223,11 +1223,6 @@ static void rgb_to_lcd16(const SkGdiRGB* SK_RESTRICT src, size_t srcRB, const Sk
     }
 }
 
-static inline unsigned clamp255(unsigned x) {
-    SkASSERT(x <= 256);
-    return x - (x >> 8);
-}
-
 void SkScalerContext_GDI::generateImage(const SkGlyph& glyph) {
     SkASSERT(fDDC);