support a8

Most of this is plumbing through the full paint to shaders instead of just the filter quality.

CQ_INCLUDE_TRYBOTS=skia.primary:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD

Change-Id: I6afde07566afa3a4391c24dca7017a9a4f5ec700
Reviewed-on: https://skia-review.googlesource.com/5317
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Reed <reed@google.com>
diff --git a/src/image/SkImageShader.h b/src/image/SkImageShader.h
index e3bab5c..074ecca 100644
--- a/src/image/SkImageShader.h
+++ b/src/image/SkImageShader.h
@@ -38,7 +38,7 @@
     SkImage* onIsAImage(SkMatrix*, TileMode*) const override;
 
     bool onAppendStages(SkRasterPipeline*, SkColorSpace*, SkFallbackAlloc*,
-                        const SkMatrix& ctm, SkFilterQuality) const override;
+                        const SkMatrix& ctm, const SkPaint&) const override;
 
     sk_sp<SkImage>  fImage;
     const TileMode  fTileModeX;