ozone: Allocate scanout buffer according to KMS modifiers

ui/ozone/platform/drm/gpu/crtc_controller.h

Index: ui/ozone/platform/drm/gpu/crtc_controller.h
diff --git a/ui/ozone/platform/drm/gpu/crtc_controller.h b/ui/ozone/platform/drm/gpu/crtc_controller.h
index f332ce54da613cce9e2520be4ae71ff6669768d1..fc1cb6b571f7045b6cd3540dbd267e3fb50d13e9 100644
--- a/ui/ozone/platform/drm/gpu/crtc_controller.h
+++ b/ui/ozone/platform/drm/gpu/crtc_controller.h
@@ -58,6 +58,9 @@ class CrtcController : public base::SupportsWeakPtr<CrtcController> {
   // |fourcc_format| format.
   bool IsFormatSupported(uint32_t fourcc_format, uint32_t z_order) const;
 
+  uint32_t GetFormatModifiers(uint32_t format,

[Daniele Castagna, 2016/12/16 00:27:41]

Can we use a vector here?
Something like:
std::vector<uint64_t> GetFormatModifiers(uint32_t format);

If you prefer to append to a vector, since in
HardwareDisplayController::GetFormatModifiers is needed, I'd go with something
like:


void AppendFormatModifiers(uint32_t format, std::vector<uint64_t>* modifiers);

[hoegsberg1, 2016/12/17 01:10:49]

I like the vector, will update. Don't like AppendFormatModifiers, since it's not
supposed to be used in a way where we append to modifiers already in the vector
- it expects an empty vector and sets it to the entire set of modifiers.

+			      uint64_t *modifiers, uint32_t count);
+
   // Called if the page flip event wasn't scheduled (ie: page flip fails). This
   // will then signal the request such that the caller doesn't wait for the
   // event forever.