Delete dead code. SkBitmapHasher has not been used since gm.

gyp/utils.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 'utils' 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 17 matching lines @@
         '<(skia_include_path)/utils/SkPaintFilterCanvas.h',
         '<(skia_include_path)/utils/SkParse.h',
         '<(skia_include_path)/utils/SkParsePath.h',
         '<(skia_include_path)/utils/SkPictureUtils.h',
         '<(skia_include_path)/utils/SkRandom.h',
         '<(skia_include_path)/utils/SkRTConf.h',
         '<(skia_include_path)/utils/SkTextBox.h',
 
         '<(skia_src_path)/utils/SkBase64.cpp',
         '<(skia_src_path)/utils/SkBase64.h',
-        '<(skia_src_path)/utils/SkBitmapHasher.cpp',
-        '<(skia_src_path)/utils/SkBitmapHasher.h',
         '<(skia_src_path)/utils/SkBitmapSourceDeserializer.cpp',
         '<(skia_src_path)/utils/SkBitmapSourceDeserializer.h',
         '<(skia_src_path)/utils/SkBitSet.cpp',
         '<(skia_src_path)/utils/SkBitSet.h',
         '<(skia_src_path)/utils/SkBoundaryPatch.cpp',
         '<(skia_src_path)/utils/SkFrontBufferedStream.cpp',
         '<(skia_src_path)/utils/SkCamera.cpp',
         '<(skia_src_path)/utils/SkCanvasStack.h',
         '<(skia_src_path)/utils/SkCanvasStack.cpp',
         '<(skia_src_path)/utils/SkCanvasStateUtils.cpp',
@@ skipping 70 matching lines @@
 
         #testing
         '<(skia_src_path)/fonts/SkGScalerContext.cpp',
         '<(skia_src_path)/fonts/SkGScalerContext.h',
         '<(skia_src_path)/fonts/SkRandomScalerContext.cpp',
         '<(skia_src_path)/fonts/SkRandomScalerContext.h',
         '<(skia_src_path)/fonts/SkTestScalerContext.cpp',
         '<(skia_src_path)/fonts/SkTestScalerContext.h',
     ],
 }