More general version of image filtering; reworked to be robust and easier to SSE

gm/filterbitmap.cpp

Index: gm/filterbitmap.cpp
diff --git a/gm/filterbitmap.cpp b/gm/filterbitmap.cpp
index 830790c03c2e04786b46303125e371863744351b..b7857f4af56712cee03ef24bcc1bb1b8222c2b60 100644
--- a/gm/filterbitmap.cpp
+++ b/gm/filterbitmap.cpp
@@ -35,7 +35,7 @@ static void draw_col(SkCanvas* canvas, const SkBitmap& bm, const SkMatrix& mat,
     canvas->translate(dx, 0);
     canvas->drawBitmapMatrix(bm, mat, &paint);
 
-    paint.setFlags(paint.getFlags() | SkPaint::kBicubicFilterBitmap_Flag);
+    paint.setFlags(paint.getFlags() | SkPaint::kHighQualityFilterBitmap_Flag);
     canvas->translate(dx, 0);
     canvas->drawBitmapMatrix(bm, mat, &paint);
 }