Stop supporting HW dither

src/gpu/GrPipelineBuilder.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrPipelineBuilder_DEFINED
 #define GrPipelineBuilder_DEFINED
 
@@ skipping 278 matching lines @@
     ///////////////////////////////////////////////////////////////////////////
     /// @name State Flags
     ////
 
     /**
      *  Flags that affect rendering. Controlled using enable/disableState(). All
      *  default to disabled.
      */
     enum Flags {
         /**
-         * Perform dithering. TODO: Re-evaluate whether we need this bit
-         */
-        kDither_Flag        = 0x01,
-        /**
          * Perform HW anti-aliasing. This means either HW FSAA, if supported by the render target,
          * or smooth-line rendering if a line primitive is drawn and line smoothing is supported by
          * the 3D API.
          */
-        kHWAntialias_Flag   = 0x02,
+        kHWAntialias_Flag   = 0x01,
 
         /**
          * Modifies the vertex shader so that vertices will be positioned at pixel centers.
          */
-        kSnapVerticesToPixelCenters_Flag = 0x04,
+        kSnapVerticesToPixelCenters_Flag = 0x02,
 
         kLast_Flag = kSnapVerticesToPixelCenters_Flag,
     };
 
-    bool isDither() const { return SkToBool(fFlags & kDither_Flag); }
     bool isHWAntialias() const { return SkToBool(fFlags & kHWAntialias_Flag); }
     bool snapVerticesToPixelCenters() const {
         return SkToBool(fFlags & kSnapVerticesToPixelCenters_Flag); }
 
     /**
      * Enable render state settings.
      *
      * @param flags bitfield of Flags specifying the states to enable
      */
     void enableState(uint32_t flags) { fFlags |= flags; }
@@ skipping 99 matching lines @@
     FragmentProcessorArray                  fCoverageFragmentProcessors;
     GrClip                                  fClip;
 
     mutable GrProcOptInfo fColorProcInfo;
     mutable GrProcOptInfo fCoverageProcInfo;
 
     friend class GrPipeline;
 };
 
 #endif