Add index-8 sampler to the pipeline.

src/core/SkLinearBitmapPipeline.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkLinearBitmapPipeline_DEFINED
 #define SkLinearBitmapPipeline_DEFINED
 
@@ skipping 48 matching lines @@
         mutable Space fSpace;
     };
 
     class PointProcessorInterface;
     class BilerpProcessorInterface;
     class PixelPlacerInterface;
 
     // These values were generated by the assert above in PolymorphicUnion.
     using MatrixStage = PolymorphicUnion<PointProcessorInterface, 160>;
     using TileStage   = PolymorphicUnion<PointProcessorInterface, 160>;
-    using SampleStage = PolymorphicUnion<BilerpProcessorInterface, 80>;
+    using SampleStage = PolymorphicUnion<BilerpProcessorInterface,100>;
     using PixelStage  = PolymorphicUnion<PixelPlacerInterface,     80>;
 
 private:
     PointProcessorInterface* fFirstStage;
     MatrixStage fMatrixStage;
     TileStage   fTiler;
     SampleStage fSampleStage;
     PixelStage  fPixelStage;
 };
 
 #endif  // SkLinearBitmapPipeline_DEFINED