ozone: Allocate scanout buffers according to KMS modifiers.

ui/ozone/platform/drm/gpu/hardware_display_controller.h

Index: ui/ozone/platform/drm/gpu/hardware_display_controller.h
diff --git a/ui/ozone/platform/drm/gpu/hardware_display_controller.h b/ui/ozone/platform/drm/gpu/hardware_display_controller.h
index bfb34739865588a6782ba0edcb081cebcd4eecbe..eda2ce381380235565367a3631c9a45d4d590155 100644
--- a/ui/ozone/platform/drm/gpu/hardware_display_controller.h
+++ b/ui/ozone/platform/drm/gpu/hardware_display_controller.h
@@ -127,6 +127,10 @@ class HardwareDisplayController {
 
   bool IsFormatSupported(uint32_t fourcc_format, uint32_t z_order) const;
 
+  // Return the supported modifiers for |fourcc_format| for this
+  // controller.
+  std::vector<uint64_t> GetFormatModifiers(uint32_t fourcc_format);
+
   // Set the hardware cursor to show the contents of |surface|.
   bool SetCursor(const scoped_refptr<ScanoutBuffer>& buffer);