Add NativePixmapHandle type & interface for exporting them

ui/ozone/ozone.gyp

 # Copyright 2013 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,
     # Normally, the external_ozone_platform* variables below can be
     # overridden by supplement.gypi which must exist exactly one level
     # below the top-level src directory. They can now also be set in
@@ skipping 94 matching lines @@
         'common/gpu/ozone_gpu_message_params.h',
         'common/gpu/ozone_gpu_messages.h',
         'common/native_display_delegate_ozone.cc',
         'common/native_display_delegate_ozone.h',
         'common/stub_client_native_pixmap_factory.cc',
         'common/stub_client_native_pixmap_factory.h',
         'common/stub_overlay_manager.cc',
         'common/stub_overlay_manager.h',
         'platform_selection.cc',
         'platform_selection.h',
+        'public/client_native_pixmap.h',
         'public/client_native_pixmap_factory.cc',
         'public/client_native_pixmap_factory.h',
         'public/input_controller.cc',
         'public/input_controller.h',
         'public/ozone_gpu_test_helper.cc',
         'public/ozone_gpu_test_helper.h',
         'public/ozone_platform.cc',
         'public/ozone_platform.h',
         'public/ozone_switches.cc',
         'public/ozone_switches.h',
@@ skipping 101 matching lines @@
         'platform/drm/gbm.gypi',
       ],
     }],
     ['<(ozone_platform_test) == 1', {
       'includes': [
         'platform/test/test.gypi',
       ],
     }],
   ],
 }