gpu: support R16 GPUMemoryBuffer

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 7d35a2a6c252fc4925ce6c3e6e0850518d80b138..02017de0ab78fd53a6bbdaca4bad0e4ab5157aff 100644
--- a/ui/ozone/platform/drm/common/drm_util.cc
+++ b/ui/ozone/platform/drm/common/drm_util.cc
@@ -17,6 +17,11 @@
 #include "base/memory/ptr_util.h"
 #include "ui/display/util/edid_parser.h"
 
+#if !defined(DRM_FORMAT_R16)
+// TODO(riju): after libdrm has this definition, remove it.

[reveman, 2017/06/20 18:45:38]

nit: add a bug number here

[riju_, 2017/06/21 07:53:19]

Done.

+#define DRM_FORMAT_R16 fourcc_code('R', '1', '6', ' ')
+#endif
+
 namespace ui {
 
 namespace {
@@ -363,6 +368,8 @@ int GetFourCCFormatFromBufferFormat(gfx::BufferFormat format) {
   switch (format) {
     case gfx::BufferFormat::R_8:
       return DRM_FORMAT_R8;
+    case gfx::BufferFormat::R_16:
+      return DRM_FORMAT_R16;
     case gfx::BufferFormat::RG_88:
       return DRM_FORMAT_GR88;
     case gfx::BufferFormat::RGBA_8888: