[Chromecast] Rename disable_display flag to is_cast_audio_only.

ui/ozone/platform/cast/ozone_platform_cast.cc

Index: ui/ozone/platform/cast/ozone_platform_cast.cc
diff --git a/ui/ozone/platform/cast/ozone_platform_cast.cc b/ui/ozone/platform/cast/ozone_platform_cast.cc
index d41708da534c745336e0a8d53a084cad916e36cb..77b119be8400f66bfac5d8c16cc1bcc1f59dcfa6 100644
--- a/ui/ozone/platform/cast/ozone_platform_cast.cc
+++ b/ui/ozone/platform/cast/ozone_platform_cast.cc
@@ -88,10 +88,10 @@ class OzonePlatformCast : public OzonePlatform {
     // or if we're an audio-only build.
     // Note: switch is kDisableGpu from content/public/common/content_switches.h
     bool enable_dummy_software_rendering = true;
-#if !BUILDFLAG(DISABLE_DISPLAY)
+#if !BUILDFLAG(IS_CAST_AUDIO_ONLY)
     enable_dummy_software_rendering =
         base::CommandLine::ForCurrentProcess()->HasSwitch("disable-gpu");
-#endif  // BUILDFLAG(DISABLE_DISPLAY)
+#endif  // BUILDFLAG(IS_CAST_AUDIO_ONLY)
 
     if (enable_dummy_software_rendering)
       surface_factory_.reset(new SurfaceFactoryCast());