Delete dead BitmapRegionDecoder code in tools

gyp/tools.gyp

 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
     # GYP file to build various tools.
 #
 # To build on Linux:
 #  ./gyp_skia tools.gyp && make tools
 #
 {
@@ skipping 36 matching lines @@
         ],
       ],
     },
     {
       'target_name': 'bitmap_region_decoder',
       'type': 'static_library',
       'sources': [
         '../tools/SkBitmapRegionCanvas.cpp',
         '../tools/SkBitmapRegionCodec.cpp',
         '../tools/SkBitmapRegionDecoder.cpp',
-        '../tools/SkBitmapRegionSampler.cpp',
       ],
       'include_dirs': [
         '../include/private',
         '../src/codec',
       ],
       'dependencies': [
         'skia_lib.gyp:skia_lib',
       ],
       'direct_dependent_settings': {
         'include_dirs': [
@@ skipping 670 matching lines @@
               'flags.gyp:flags',
               'skia_lib.gyp:skia_lib',
               'resources',
             ],
           },
         ],
       },
     ],
   ],
 }