DirectWrite to use aliased if ClearType is empty.

src/ports/SkScalerContext_win_dw.h

Index: src/ports/SkScalerContext_win_dw.h
diff --git a/src/ports/SkScalerContext_win_dw.h b/src/ports/SkScalerContext_win_dw.h
index e8eff0d6ce91f15d60005a49da63dea7878975b6..e9eab94de12435bc3d77f3a84a7a3b974aec15d7 100644
--- a/src/ports/SkScalerContext_win_dw.h
+++ b/src/ports/SkScalerContext_win_dw.h
@@ -33,7 +33,14 @@ protected:
     virtual void generateFontMetrics(SkPaint::FontMetrics*) SK_OVERRIDE;
 
 private:
-    const void* drawDWMask(const SkGlyph& glyph);
+    const void* drawDWMask(const SkGlyph& glyph,
+                           DWRITE_RENDERING_MODE renderingMode,
+                           DWRITE_TEXTURE_TYPE textureType);
+
+    void getBoundingBox(SkGlyph* glyph,
+                        DWRITE_RENDERING_MODE renderingMode,
+                        DWRITE_TEXTURE_TYPE textureType,
+                        RECT* bbox);
 
     SkTDArray<uint8_t> fBits;
     /** The total matrix without the text height scale. */