Add bilerp filtering.

bench/SkLinearBitmapPipelineBench.cpp

Index: bench/SkLinearBitmapPipelineBench.cpp
diff --git a/bench/SkLinearBitmapPipelineBench.cpp b/bench/SkLinearBitmapPipelineBench.cpp
index 149e9e2bad17c88b7f8e21530dae42d263917c46..cc5d0850e86161b9ac6109299db65f767180d821 100644
--- a/bench/SkLinearBitmapPipelineBench.cpp
+++ b/bench/SkLinearBitmapPipelineBench.cpp
@@ -134,7 +134,15 @@ struct SkBitmapFPGeneral final : public CommonBitmapFPBenchmark {
 
         SkAutoTMalloc<SkPM4f> FPbuffer(width*height);
 
-        SkLinearBitmapPipeline pipeline{fInvert, fXTile, fYTile, fInfo, fBitmap.get(), };
+        SkFilterQuality filterQuality;
+        if (fUseBilerp) {
+            filterQuality = SkFilterQuality::kLow_SkFilterQuality;
+        } else {
+            filterQuality = SkFilterQuality::kNone_SkFilterQuality;
+        }
+
+        SkLinearBitmapPipeline pipeline{
+            fInvert, filterQuality, fXTile, fYTile, fInfo, fBitmap.get() };
 
         int count = 100;