Add subsetting to SkScanlineDecoder

gyp/visualbench.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 visual bench tool
 {
   'includes': [
     'apptype_console.gypi',
   ],
   'targets': [
     {
       'target_name': 'visualbench',
       'type': 'executable',
       'includes' : [
         'gmslides.gypi',
       ],
       'include_dirs' : [
         '../bench',
         '../include/gpu',
         '../include/private',
+        '../src/codec',
         '../src/core',
         '../src/effects',
         '../src/images',
       ],
       'sources': [
         '../gm/gm.cpp',
         '<!@(python find.py ../tools/VisualBench "*.cpp")',
         '<!@(python find.py ../tools/VisualBench "*.h")',
         '<!@(python find.py ../bench "*.cpp")',
       ],
@@ skipping 24 matching lines @@
               '-landroid',
               '-lGLESv2',
               '-lEGL',
             ],
           },
         }],
       ],
     },
   ],
 }