ozone: Allocate scanout buffers according to KMS modifiers.

ui/ozone/platform/drm/gpu/gbm_buffer_base.cc

Index: ui/ozone/platform/drm/gpu/gbm_buffer_base.cc
diff --git a/ui/ozone/platform/drm/gpu/gbm_buffer_base.cc b/ui/ozone/platform/drm/gpu/gbm_buffer_base.cc
index a031b80061ae8be172e7b6a3f371be508d4dc7ad..83cea290d14e8aeab3df0883959e8de900573cdb 100644
--- a/ui/ozone/platform/drm/gpu/gbm_buffer_base.cc
+++ b/ui/ozone/platform/drm/gpu/gbm_buffer_base.cc
@@ -15,7 +15,9 @@ namespace ui {
 GbmBufferBase::GbmBufferBase(const scoped_refptr<GbmDevice>& drm,
                              gbm_bo* bo,
                              uint32_t format,
-                             uint32_t flags)
+                             uint32_t flags,
+                             uint64_t modifier,
+                             uint32_t addfb_flags)
     : drm_(drm), bo_(bo) {
   if (flags & GBM_BO_USE_SCANOUT) {
     DCHECK(bo_);
@@ -27,10 +29,17 @@ GbmBufferBase::GbmBufferBase(const scoped_refptr<GbmDevice>& drm,
     uint32_t strides[4] = {0};
     strides[0] = gbm_bo_get_stride(bo);
     uint32_t offsets[4] = {0};
+    uint64_t modifiers[4] = {0};
+    modifiers[0] = modifier;
 
+    // AddFramebuffer2 only considers the modifiers if addfb_flags has
+    // DRM_MODE_FB_MODIFIERS set. We only set that when we've created
+    // a bo with modifiers, otherwise, we rely on the "no modifiers"
+    // behavior doing the right thing.
     if (!drm_->AddFramebuffer2(gbm_bo_get_width(bo), gbm_bo_get_height(bo),
                                framebuffer_pixel_format_, handles, strides,
-                               offsets, &framebuffer_, 0)) {
+                               offsets, modifiers, &framebuffer_,
+                               addfb_flags)) {
       PLOG(ERROR) << "Failed to register buffer";
       return;
     }