ozone: Allocate scanout buffers according to KMS modifiers.

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/ozone/platform/drm/gpu/hardware_display_controller.h"
 
 #include <drm.h>
 #include <string.h>
 #include <xf86drm.h>
 #include <utility>
@@ skipping 127 matching lines @@
                                                   uint32_t z_order) const {
   for (size_t i = 0; i < crtc_controllers_.size(); ++i) {
     // Make sure all displays have overlay to support this format.
     if (!crtc_controllers_[i]->IsFormatSupported(fourcc_format, z_order))
       return false;
   }
 
   return true;
 }
 
+std::vector<uint64_t> HardwareDisplayController::GetFormatModifiers(
+    uint32_t format) {
+  std::vector<uint64_t> modifiers;
+
+  if (crtc_controllers_.empty())
+    return modifiers;
+
+  modifiers = crtc_controllers_[0]->GetFormatModifiers(format);
+
+  for (size_t i = 1; i < crtc_controllers_.size(); ++i) {
+    std::vector<uint64_t> other =
+        crtc_controllers_[i]->GetFormatModifiers(format);
+    std::vector<uint64_t> intersection;
+
+    std::set_intersection(modifiers.begin(), modifiers.end(), other.begin(),
+                          other.end(), std::back_inserter(intersection));
+    modifiers = std::move(intersection);
+  }
+
+  return modifiers;
+}
+
 bool HardwareDisplayController::SetCursor(
     const scoped_refptr<ScanoutBuffer>& buffer) {
   bool status = true;
 
   if (is_disabled_)
     return true;
 
   for (const auto& controller : crtc_controllers_)
     status &= controller->SetCursor(buffer);
 
@@ skipping 113 matching lines @@
 
 scoped_refptr<DrmDevice> HardwareDisplayController::GetAllocationDrmDevice()
     const {
   DCHECK(!crtc_controllers_.empty());
   // TODO(dnicoara) When we support mirroring across DRM devices, figure out
   // which device should be used for allocations.
   return crtc_controllers_[0]->drm();
 }
 
 }  // namespace ui