Move SkGLContext and some GrGLInterface implementations to skgputest module

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',
       'include_dirs': [
         '../src/core',
+        '../src/gpu',
         '../src/ports',
         '../tools/debugger',
         '../tools/json',
       ],
       'sources': [ 
         # Stuff for the debug canvas
         '../tools/debugger/SkDrawCommand.h',
         '../tools/debugger/SkDrawCommand.cpp',
         '../tools/debugger/SkDebugCanvas.h',
         '../tools/debugger/SkDebugCanvas.cpp',
@@ skipping 12 matching lines @@
         'microhttpd.gyp:microhttpd',
         'skia_lib.gyp:skia_lib',
         'tools.gyp:crash_handler',
         'tools.gyp:proc_stats',
         'tools.gyp:resources',
         'tools.gyp:url_data_manager',
       ],
     },
   ],
 }