Make SkGLContext lifetime more well-defined

gyp/pathops_unittest.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 pathops unit tests.
 {
   'includes': [
     'apptype_console.gypi',
   ],
   'targets': [
@@ skipping 23 matching lines @@
           ],
           'libraries!': [
             '-lz',
             '-llog',
           ],
         }],
         [ 'skia_gpu == 1', {
           'include_dirs': [
             '../src/gpu',
           ],
+          'sources': [
+            '../src/gpu/GrContextFactory.cpp',
+            '../src/gpu/GrContextFactory.h',
+          ]
         }],
       ],
     },
   ],
 }