Move GLContext creation from //ui/gl to //ui/gl/init.

ui/gl/gl.gyp

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'variables': {
     'chromium_code': 1,
   },
 
   'targets': [
@@ skipping 31 matching lines @@
         'android/surface_texture_listener.cc',
         'android/surface_texture_listener.h',
         'gl_bindings.cc',
         'gl_bindings.h',
         'gl_bindings_autogen_gl.cc',
         'gl_bindings_autogen_gl.h',
         'gl_bindings_autogen_osmesa.cc',
         'gl_bindings_autogen_osmesa.h',
         'gl_context.cc',
         'gl_context.h',
-        'gl_context_android.cc',
-        'gl_context_mac.mm',
         'gl_context_osmesa.cc',
         'gl_context_osmesa.h',
-        'gl_context_ozone.cc',
         'gl_context_stub.cc',
         'gl_context_stub.h',
         'gl_context_stub_with_extensions.cc',
         'gl_context_stub_with_extensions.h',
-        'gl_context_win.cc',
-        'gl_context_x11.cc',
         'gl_enums.cc',
         'gl_enums.h',
         'gl_enums_implementation_autogen.h',
         'gl_export.h',
         'gl_fence.cc',
         'gl_fence.h',
         'gl_fence_arb.cc',
         'gl_fence_arb.h',
         'gl_fence_nv.cc',
         'gl_fence_nv.h',
@@ skipping 311 matching lines @@
           ],
           'variables': {
             'jni_gen_package': 'ui/gl',
           },
           'includes': [ '../../build/jni_generator.gypi' ],
         },
       ],
     }],
   ],
 }