Propagate filter mode when rendering Alpha8 bitmaps

src/core/SkDraw.cpp

Index: src/core/SkDraw.cpp
diff --git a/src/core/SkDraw.cpp b/src/core/SkDraw.cpp
index 884794261dcad45130cb345e5325075109aa30f2..f838cc18c28397ff7b137d748b0d7a612b994074 100644
--- a/src/core/SkDraw.cpp
+++ b/src/core/SkDraw.cpp
@@ -1240,6 +1240,7 @@ void SkDraw::drawBitmapAsMask(const SkBitmap& bitmap, const SkPaint& paint) cons
             // we manually build a shader and draw that into our new mask
             SkPaint tmpPaint;
             tmpPaint.setFlags(paint.getFlags());
+            tmpPaint.setFilterQuality(paint.getFilterQuality());
             SkAutoBitmapShaderInstall install(bitmap, tmpPaint);
             SkRect rr;
             rr.set(0, 0, SkIntToScalar(bitmap.width()),