Stop supporting HW dither

src/gpu/GrPipeline.cpp

Index: src/gpu/GrPipeline.cpp
diff --git a/src/gpu/GrPipeline.cpp b/src/gpu/GrPipeline.cpp
index 1d7b71f605d57c06c1d323ee48602948a6fffe8e..80e3cbdf6923779a1e908c1f5f6c07d4afff3f86 100644
--- a/src/gpu/GrPipeline.cpp
+++ b/src/gpu/GrPipeline.cpp
@@ -66,9 +66,6 @@ GrPipeline* GrPipeline::CreateAt(void* memory, const CreateArgs& args,
     if (builder.isHWAntialias()) {
         pipeline->fFlags |= kHWAA_Flag;
     }
-    if (builder.isDither()) {
-        pipeline->fFlags |= kDither_Flag;
-    }
     if (builder.snapVerticesToPixelCenters()) {
         pipeline->fFlags |= kSnapVertices_Flag;
     }