Bug 1616185 [Wayland] Build VA-API support for ffmpeg58 and Wayland only, r=jya

Differential Revision: https://phabricator.services.mozilla.com/D63134

--HG--
extra : moz-landing-system : lando

dom/media/platforms/ffmpeg/ffmpeg58/moz.build

@@ -25,5 +25,10 @@ if CONFIG['CC_TYPE'] == 'gcc':
   CXXFLAGS += [
     '-Wno-attributes',
   ]
+if CONFIG['MOZ_WAYLAND']:
+  CXXFLAGS += CONFIG['TK_CFLAGS']
+  CXXFLAGS += CONFIG['MOZ_WAYLAND_CFLAGS']
+  DEFINES['MOZ_WAYLAND_USE_VAAPI'] = 1
+  include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'