ozone: Let BGRA fullscreen overlays replace primary plane.

ui/ozone/platform/drm/gpu/hardware_display_plane_manager.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_plane_manager.h"
 
 #include <drm_fourcc.h>
 
 #include <set>
 #include <utility>
@@ skipping 216 matching lines @@
     CrtcController* crtc) {
   int crtc_index = LookupCrtcIndex(crtc_id);
   if (crtc_index < 0) {
     LOG(ERROR) << "Cannot find crtc " << crtc_id;
     return false;
   }
 
   size_t plane_idx = 0;
   HardwareDisplayPlane* primary_plane = nullptr;
   gfx::Rect primary_display_bounds;
-  uint32_t primary_format;
   for (const auto& plane : overlay_list) {
     HardwareDisplayPlane* hw_plane =
         FindNextUnusedPlane(&plane_idx, crtc_index, plane);
     if (!hw_plane) {
       LOG(ERROR) << "Failed to find a free plane for crtc " << crtc_id;
       ResetCurrentPlaneList(plane_list);
       return false;
     }
 
     gfx::Rect fixed_point_rect;
@@ skipping 10 matching lines @@
       fixed_point_rect = gfx::Rect(to_fixed_point(crop_rect.x()),
                                    to_fixed_point(crop_rect.y()),
                                    to_fixed_point(crop_rect.width()),
                                    to_fixed_point(crop_rect.height()));
     }
 
     // If Overlay completely covers primary and isn't transparent, than use
     // it as primary. This reduces the no of planes which need to be read in
     // display controller side.
     if (primary_plane) {
-      bool needs_blending = true;
-      if (fourcc_format == DRM_FORMAT_XRGB8888)
-        needs_blending = false;
-      // TODO(kalyank): Check if we can move this optimization to
-      // DrmOverlayCandidatesHost.
-      if (!needs_blending && primary_format == fourcc_format &&
+      // TODO(dcastagna): Check if we can move this optimization to
+      // GLRenderer::ScheduleOverlays.
+      // Note that Chromium compositor promotes buffers to overlays (ARGB
+      // ones too) only if blending is not needed.
+      if ((fourcc_format == DRM_FORMAT_XRGB8888 ||
+           fourcc_format == DRM_FORMAT_ARGB8888) &&
           primary_display_bounds == plane.display_bounds) {
         ResetCurrentPlaneList(plane_list);
         hw_plane = primary_plane;
       }
     } else {
       primary_plane = hw_plane;
       primary_display_bounds = plane.display_bounds;
-      primary_format = fourcc_format;
     }
 
     if (!SetPlaneData(plane_list, hw_plane, plane, crtc_id, fixed_point_rect,
                       crtc)) {
       ResetCurrentPlaneList(plane_list);
       return false;
     }
 
     plane_list->plane_list.push_back(hw_plane);
     hw_plane->set_owning_crtc(crtc_id);
@@ skipping 34 matching lines @@
       break;
     } else {
       plane_z_order++;
     }
   }
 
   return format_supported;
 }
 
 }  // namespace ui