Stop supporting HW dither

src/gpu/GrPipeline.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrPipeline.h"
 
 #include "GrCaps.h"
@@ skipping 48 matching lines @@
     pipeline->fRenderTarget.reset(builder.fRenderTarget.get());
     SkASSERT(pipeline->fRenderTarget);
     pipeline->fScissorState = *args.fScissor;
     pipeline->fStencilSettings = builder.getStencil();
     pipeline->fDrawFace = builder.getDrawFace();
 
     pipeline->fFlags = 0;
     if (builder.isHWAntialias()) {
         pipeline->fFlags |= kHWAA_Flag;
     }
-    if (builder.isDither()) {
-        pipeline->fFlags |= kDither_Flag;
-    }
     if (builder.snapVerticesToPixelCenters()) {
         pipeline->fFlags |= kSnapVertices_Flag;
     }
 
     int firstColorProcessorIdx = args.fColorPOI.firstEffectiveProcessorIndex();
 
     // TODO: Once we can handle single or four channel input into coverage GrFragmentProcessors
     // then we can use GrPipelineBuilder's coverageProcInfo (like color above) to set this initial
     // information.
     int firstCoverageProcessorIdx = 0;
@@ skipping 98 matching lines @@
     }
 
     for (int i = 0; i < a.numFragmentProcessors(); i++) {
         if (!a.getFragmentProcessor(i).isEqual(b.getFragmentProcessor(i), ignoreCoordTransforms)) {
             return false;
         }
     }
     return true;
 }