move SkDither.h to private, remove unused shadeSpan16

gyp/core.gypi

 # 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 this gypi to include all 'core' files
 # The parent gyp/gypi file must define
 #       'skia_src_path'     e.g. skia/trunk/src
 #       'skia_include_path' e.g. skia/trunk/include
 #
 # The skia build defines these in common_variables.gypi
@@ skipping 76 matching lines @@
         '<(skia_src_path)/core/SkDescriptor.h',
         '<(skia_src_path)/core/SkDevice.cpp',
         '<(skia_src_path)/core/SkDeviceLooper.cpp',
         '<(skia_src_path)/core/SkDeviceProfile.cpp',
         '<(skia_src_path)/core/SkDiscardableMemory.h',
         '<(skia_src_path)/lazy/SkDiscardableMemoryPool.cpp',
         '<(skia_src_path)/lazy/SkDiscardablePixelRef.cpp',
         '<(skia_src_path)/core/SkDistanceFieldGen.cpp',
         '<(skia_src_path)/core/SkDistanceFieldGen.h',
         '<(skia_src_path)/core/SkDither.cpp',
+        '<(skia_src_path)/core/SkDither.h',
         '<(skia_src_path)/core/SkDraw.cpp',
         '<(skia_src_path)/core/SkDrawable.cpp',
         '<(skia_src_path)/core/SkDrawLooper.cpp',
         '<(skia_src_path)/core/SkDrawProcs.h',
         '<(skia_src_path)/core/SkEdgeBuilder.cpp',
         '<(skia_src_path)/core/SkEdgeBuilder.h',
         '<(skia_src_path)/core/SkEdgeClipper.cpp',
         '<(skia_src_path)/core/SkEdgeClipper.h',
         '<(skia_src_path)/core/SkEmptyShader.h',
         '<(skia_src_path)/core/SkEndian.h',
@@ skipping 214 matching lines @@
         '<(skia_include_path)/core/SkCanvas.h',
         '<(skia_include_path)/core/SkChunkAlloc.h',
         '<(skia_include_path)/core/SkClipStack.h',
         '<(skia_include_path)/core/SkColor.h',
         '<(skia_include_path)/core/SkColorFilter.h',
         '<(skia_include_path)/core/SkColorPriv.h',
         '<(skia_include_path)/core/SkComposeShader.h',
         '<(skia_include_path)/core/SkData.h',
         '<(skia_include_path)/core/SkDeque.h',
         '<(skia_include_path)/core/SkDevice.h',
-        '<(skia_include_path)/core/SkDither.h',
         '<(skia_include_path)/core/SkDraw.h',
         '<(skia_include_path)/core/SkDrawable.h',
         '<(skia_include_path)/core/SkDrawFilter.h',
         '<(skia_include_path)/core/SkDrawLooper.h',
         '<(skia_include_path)/core/SkError.h',
         '<(skia_include_path)/core/SkFixed.h',
         '<(skia_include_path)/core/SkFlattenable.h',
         '<(skia_include_path)/core/SkFlattenableSerialization.h',
         '<(skia_include_path)/core/SkFontHost.h',
         '<(skia_include_path)/core/SkFontStyle.h',
@@ skipping 128 matching lines @@
         '<(skia_src_path)/pathops/SkPathOpsLine.h',
         '<(skia_src_path)/pathops/SkPathOpsPoint.h',
         '<(skia_src_path)/pathops/SkPathOpsQuad.h',
         '<(skia_src_path)/pathops/SkPathOpsRect.h',
         '<(skia_src_path)/pathops/SkPathOpsTSect.h',
         '<(skia_src_path)/pathops/SkPathOpsTypes.h',
         '<(skia_src_path)/pathops/SkPathWriter.h',
         '<(skia_src_path)/pathops/SkReduceOrder.h',
     ],
 }