Add support to send optimal format as part of ScheduleOverlayPlane

ui/ozone/platform/drm/host/drm_overlay_candidates_host.cc

 // Copyright 2015 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/host/drm_overlay_candidates_host.h"
 
 #include <algorithm>
 
 #include "ui/gfx/geometry/rect_conversions.h"
 #include "ui/ozone/common/gpu/ozone_gpu_messages.h"
 #include "ui/ozone/platform/drm/host/drm_gpu_platform_support_host.h"
 #include "ui/ozone/platform/drm/host/drm_window_host.h"
 
 namespace ui {
 
 namespace {
 const size_t kMaxCacheSize = 100;
+// Optimal format for rendering on overlay.
+const gfx::BufferFormat kOverlayRenderFormat = gfx::BufferFormat::UYVY_422;
 }  // namespace
 
 bool DrmOverlayCandidatesHost::OverlayCompare::operator()(
     const OverlayCheck_Params& l,
     const OverlayCheck_Params& r) const {
   if (l.plane_z_order < r.plane_z_order)
     return true;
   if (l.plane_z_order > r.plane_z_order)
     return false;
   if (l.display_rect < r.display_rect)
@@ skipping 46 matching lines @@
   for (auto& candidate : *candidates) {
     if (!CanHandleCandidate(candidate))
       continue;
 
     OverlayCheck_Params lookup(candidate);
     if (!force_validation) {
       CompatibleParams::const_iterator last_iter =
           in_use_compatible_params_.find(lookup);
       if (last_iter != in_use_compatible_params_.end()) {
         candidate.overlay_handled = last_iter->second;
+        // TODO(kalyank): Figure out the optimal render format for overlay. We
+        // should get this from GPU process side. See http://crbug.com/553264.
+        if (candidate.plane_z_order > 0) {
+          candidate.format = kOverlayRenderFormat;
+          candidate.handle_scaling = true;
+        }
+
         compatible_candidates++;
         if (candidate.overlay_handled)
           planes_in_use++;
 
         continue;
       }
     }
 
     auto iter = cache_.Get(lookup);
     if (iter == cache_.end()) {
@@ skipping 207 matching lines @@
         break;
     }
 
     // We dont have any free hardware resources.
     if (!available_overlays)
       break;
   }
 }
 
 }  // namespace ui