SkPaint::FilterLevel -> SkFilterQuality

clone (+rebase) of https://codereview.chromium.org/1009183002/

BUG=skia:
TBR=scroggo@google.com

Review URL: https://codereview.chromium.org/1014533004
diff --git a/gm/bitmapfilters.cpp b/gm/bitmapfilters.cpp
index f1348b1..8b68d3b 100644
--- a/gm/bitmapfilters.cpp
+++ b/gm/bitmapfilters.cpp
@@ -41,7 +41,7 @@
 static SkScalar draw_set(SkCanvas* c, const SkBitmap& bm, SkScalar x,
                          SkPaint* p) {
     x += draw_bm(c, bm, x, 0, p);
-    p->setFilterLevel(SkPaint::kLow_FilterLevel);
+    p->setFilterQuality(kLow_SkFilterQuality);
     x += draw_bm(c, bm, x, 0, p);
     p->setDither(true);
     return x + draw_bm(c, bm, x, 0, p);