Ozone GBM: support R_8 format to GpuMemoryBuffers

ui/ozone/platform/drm/common/drm_util.cc

Index: ui/ozone/platform/drm/common/drm_util.cc
diff --git a/ui/ozone/platform/drm/common/drm_util.cc b/ui/ozone/platform/drm/common/drm_util.cc
index dae5dd300150ccdc4977d2a677e63d466c0d8e16..b18f28956299d585ffec970f9ce8ca0c90ec0009 100644
--- a/ui/ozone/platform/drm/common/drm_util.cc
+++ b/ui/ozone/platform/drm/common/drm_util.cc
@@ -26,6 +26,11 @@
 #define DRM_CAP_CURSOR_HEIGHT 0x9
 #endif
 
+#if !defined(DRM_FORMAT_R8)
+// TODO(dshwang): after most linux and libdrm has this definition, remove it.
+#define DRM_FORMAT_R8 fourcc_code('R', '8', ' ', ' ')
+#endif
+
 namespace ui {
 
 namespace {
@@ -318,6 +323,8 @@ DisplaySnapshot_Params CreateDisplaySnapshotParams(
 
 int GetFourCCFormatFromBufferFormat(gfx::BufferFormat format) {
   switch (format) {
+    case gfx::BufferFormat::R_8:
+      return DRM_FORMAT_R8;
     case gfx::BufferFormat::RGBA_8888:
       return DRM_FORMAT_ABGR8888;
     case gfx::BufferFormat::RGBX_8888:
@@ -336,6 +343,8 @@ int GetFourCCFormatFromBufferFormat(gfx::BufferFormat format) {
 
 gfx::BufferFormat GetBufferFormatFromFourCCFormat(int format) {
   switch (format) {
+    case DRM_FORMAT_R8:
+      return gfx::BufferFormat::R_8;
     case DRM_FORMAT_ABGR8888:
       return gfx::BufferFormat::RGBA_8888;
     case DRM_FORMAT_XBGR8888: