ozone: Add overlay candidate implementation that queries support via IPC

ui/ozone/platform/drm/drm.gypi

 # Copyright 2014 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': {
     'internal_ozone_platform_deps': [
       'ozone_platform_drm',
     ],
     'internal_ozone_platform_unittest_deps': [
@@ skipping 76 matching lines @@
         'host/drm_cursor.cc',
         'host/drm_cursor.h',
         'host/drm_device_handle.cc',
         'host/drm_device_handle.h',
         'host/drm_display_host.cc',
         'host/drm_display_host.h',
         'host/drm_display_host_manager.cc',
         'host/drm_display_host_manager.h',
         'host/drm_gpu_platform_support_host.cc',
         'host/drm_gpu_platform_support_host.h',
+        'host/drm_host_overlay_candidates.cc',
+        'host/drm_host_overlay_candidates.h',
         'host/drm_native_display_delegate.cc',
         'host/drm_native_display_delegate.h',
         'host/drm_overlay_manager.cc',
         'host/drm_overlay_manager.h',
         'host/drm_window_host.cc',
         'host/drm_window_host.h',
         'host/drm_window_host_manager.cc',
         'host/drm_window_host_manager.h',
         'ozone_platform_drm.cc',
         'ozone_platform_drm.h',
@@ skipping 21 matching lines @@
           'gpu/hardware_display_controller_unittest.cc',
           'gpu/hardware_display_plane_manager_unittest.cc',
           'gpu/screen_manager_unittest.cc',
           'test/mock_drm_device.cc',
           'test/mock_drm_device.h',
         ],
       },
     },
   ],
 }