Wire up JsonCanvas in skiaserve

gyp/skiaserve.gyp

 # Copyright 2016 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 performance testbench.
 #
 {
   'includes': [
     'apptype_console.gypi',
   ],
   'targets': [
     {
       'target_name': 'skiaserve',
       'type': 'executable',
       'sources': [ 
         '<!@(python find.py ../tools/skiaserve "*.cpp")',
       ],
+      'include_dirs': [
+        '../tools/json',
+      ],
       'dependencies': [
         'flags.gyp:flags',
         'gputest.gyp:skgputest',
+        'json.gyp:json',
         'jsoncpp.gyp:jsoncpp',
         'microhttpd.gyp:microhttpd',
         'skia_lib.gyp:skia_lib',
         'tools.gyp:crash_handler',
         'tools.gyp:proc_stats',
         'tools.gyp:resources',
       ],
     },
   ],
 }