ozone: Allocate scanout buffer according to KMS modifiers

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

Index: ui/ozone/platform/drm/gpu/hardware_display_plane.cc
diff --git a/ui/ozone/platform/drm/gpu/hardware_display_plane.cc b/ui/ozone/platform/drm/gpu/hardware_display_plane.cc
index 54f59188aba79c9e711776d76a89bfae75056987..3d16a6ae9661a22d317b0289d159712ec8329524 100644
--- a/ui/ozone/platform/drm/gpu/hardware_display_plane.cc
+++ b/ui/ozone/platform/drm/gpu/hardware_display_plane.cc
@@ -5,6 +5,7 @@
 #include "ui/ozone/platform/drm/gpu/hardware_display_plane.h"
 
 #include <drm_fourcc.h>
+#include <drm_mode.h>
 
 #include "base/logging.h"
 #include "ui/ozone/platform/drm/gpu/drm_device.h"
@@ -56,9 +57,16 @@ bool HardwareDisplayPlane::CanUseForCrtc(uint32_t crtc_index) {
 
 bool HardwareDisplayPlane::Initialize(DrmDevice* drm,
                                       const std::vector<uint32_t>& formats,
+                                      const std::vector<struct drm_format_info>& format_info,
                                       bool is_dummy,
                                       bool test_only) {
   supported_formats_ = formats;
+  supported_format_info_ = format_info;
+
+  for (auto& element : supported_format_info_) {

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

Was this for debugging?

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

Yeah, removed it.

+	  LOG(ERROR) << " format info: modifier=" << element.modifier << ", formats=" << element.formats;
+  }
+
 
   if (test_only)
     return true;
@@ -112,6 +120,24 @@ const std::vector<uint32_t>& HardwareDisplayPlane::supported_formats() const {
   return supported_formats_;
 }
 
+uint32_t HardwareDisplayPlane::ModifiersForFormat(uint32_t format, uint64_t *modifiers, uint32_t count) {
+  uint32_t format_index = 0;
+  for (const auto& f : supported_formats_) {
+    if (f == format)
+      break;
+    format_index++;
+  }
+  DCHECK(format_index < supported_formats_.size());

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

nit: DCHECK_LT

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

Done - what's better about DCHECK_LT though?

+
+  uint32_t i = 0;
+  for (const auto& info : supported_format_info_) {
+    if (info.formats & (1 << format_index) && i < count)
+      modifiers[i++] = info.modifier;
+  }
+
+  return i;
+}
+
 bool HardwareDisplayPlane::InitializeProperties(
     DrmDevice* drm,
     const ScopedDrmObjectPropertyPtr& plane_props) {