ozone: Allocate scanout buffer according to KMS modifiers

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

Index: ui/ozone/platform/drm/gpu/gbm_buffer.cc
diff --git a/ui/ozone/platform/drm/gpu/gbm_buffer.cc b/ui/ozone/platform/drm/gpu/gbm_buffer.cc
index de628ac8007d89274d1472f5118bc4c130671000..c525b01af27af562b152d9dd5f381eed3f7174f2 100644
--- a/ui/ozone/platform/drm/gpu/gbm_buffer.cc
+++ b/ui/ozone/platform/drm/gpu/gbm_buffer.cc
@@ -30,12 +30,14 @@ GbmBuffer::GbmBuffer(const scoped_refptr<GbmDevice>& gbm,
                      gbm_bo* bo,
                      uint32_t format,
                      uint32_t flags,
+                     uint64_t modifier,
                      std::vector<base::ScopedFD>&& fds,
                      const gfx::Size& size,
                      const std::vector<gfx::NativePixmapPlane>&& planes)
     : GbmBufferBase(gbm, bo, format, flags),
       format_(format),
       flags_(flags),
+      modifier_(modifier),
       fds_(std::move(fds)),
       size_(size),
       planes_(std::move(planes)) {}
@@ -129,7 +131,56 @@ scoped_refptr<GbmBuffer> GbmBuffer::CreateBuffer(
         gbm_bo_get_plane_size(bo, i), gbm_bo_get_plane_format_modifier(bo, i));
   }
   scoped_refptr<GbmBuffer> buffer(new GbmBuffer(
-      gbm, bo, format, flags, std::move(fds), size, std::move(planes)));
+      gbm, bo, format, flags, 0, std::move(fds), size, std::move(planes)));
+  if (flags & GBM_BO_USE_SCANOUT && !buffer->GetFramebufferId())
+    return nullptr;
+
+  return buffer;
+}
+
+// static
+scoped_refptr<GbmBuffer> GbmBuffer::CreateBufferWithModifiers(
+    const scoped_refptr<GbmDevice>& gbm,
+    uint32_t format,
+    const gfx::Size& size,
+    uint32_t flags,
+    const uint64_t *modifiers, uint32_t nmodifiers) {
+  TRACE_EVENT2("drm", "GbmBuffer::CreateBufferWithModifiers", "device",
+               gbm->device_path().value(), "size", size.ToString());
+
+  gbm_bo* bo =
+    gbm_bo_create_with_modifiers(gbm->device(), size.width(), size.height(), format,
+				 modifiers, nmodifiers);
+  if (!bo)
+    return nullptr;
+
+  uint64_t modifier = gbm_bo_get_format_modifier(bo);
+
+  std::vector<base::ScopedFD> fds;
+  std::vector<gfx::NativePixmapPlane> planes;
+
+  for (size_t i = 0; i < gbm_bo_get_num_planes(bo); ++i) {
+    // The fd returned by gbm_bo_get_fd is not ref-counted and need to be
+    // kept open for the lifetime of the buffer.
+    base::ScopedFD fd(gbm_bo_get_plane_fd(bo, i));
+
+    // TODO(dcastagna): support multiple fds.
+    // crbug.com/642410
+    if (!i) {
+      if (!fd.is_valid()) {
+        PLOG(ERROR) << "Failed to export buffer to dma_buf";
+        gbm_bo_destroy(bo);
+        return nullptr;
+      }
+      fds.emplace_back(std::move(fd));
+    }
+
+    planes.emplace_back(
+        gbm_bo_get_plane_stride(bo, i), gbm_bo_get_plane_offset(bo, i),
+        gbm_bo_get_plane_size(bo, i), gbm_bo_get_plane_format_modifier(bo, i));
+  }
+  scoped_refptr<GbmBuffer> buffer(new GbmBuffer(
+    gbm, bo, format, flags, modifier, std::move(fds), size, std::move(planes)));
   if (flags & GBM_BO_USE_SCANOUT && !buffer->GetFramebufferId())
     return nullptr;
 
@@ -177,7 +228,7 @@ scoped_refptr<GbmBuffer> GbmBuffer::CreateBufferFromFds(
   if (use_scanout)
     flags |= GBM_BO_USE_SCANOUT;
   scoped_refptr<GbmBuffer> buffer(new GbmBuffer(
-      gbm, bo, format, flags, std::move(fds), size, std::move(planes)));
+    gbm, bo, format, 0, flags, std::move(fds), size, std::move(planes)));
   // If scanout support for buffer is expected then make sure we managed to
   // create a framebuffer for it as otherwise using it for scanout will fail.
   if (use_scanout && !buffer->GetFramebufferId())