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 3738cf27d4459d4026e10f755c1b3ccc31d4cf6a..b4898f4f0ab4d13d639b9de0b6d7a6e067bd65d4 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);