Optimize plane usage when primary is obscured by Overlay

ui/ozone/platform/drm/gpu/hardware_display_plane_manager_legacy.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_legacy.h"
 
 #include "base/bind.h"
 #include "ui/ozone/platform/drm/gpu/crtc_controller.h"
 #include "ui/ozone/platform/drm/gpu/drm_device.h"
 #include "ui/ozone/platform/drm/gpu/scanout_buffer.h"
@@ skipping 65 matching lines @@
       // This plane is being released, so we need to zero it.
       if (!drm_->PageFlipOverlay(plane->owning_crtc(), 0, gfx::Rect(),
                                  gfx::Rect(), plane->plane_id())) {
         PLOG(ERROR) << "Cannot free overlay: crtc=" << plane->owning_crtc()
                     << " plane=" << plane->plane_id();
         ret = false;
         break;
       }
     }
   }
-  plane_list->plane_list.swap(plane_list->old_plane_list);
-  plane_list->plane_list.clear();
-  plane_list->legacy_page_flips.clear();
+
+  if (ret) {
+    plane_list->plane_list.swap(plane_list->old_plane_list);
+    plane_list->plane_list.clear();
+    plane_list->legacy_page_flips.clear();
+  } else {
+    ResetCurrentPlaneList(plane_list);
+  }
+
   return ret;
 }
 
 bool HardwareDisplayPlaneManagerLegacy::SetPlaneData(
     HardwareDisplayPlaneList* plane_list,
     HardwareDisplayPlane* hw_plane,
     const OverlayPlane& overlay,
     uint32_t crtc_id,
     const gfx::Rect& src_rect,
     CrtcController* crtc) {
   if ((hw_plane->type() == HardwareDisplayPlane::kDummy) ||
       plane_list->legacy_page_flips.empty() ||
       plane_list->legacy_page_flips.back().crtc_id != crtc_id) {
     plane_list->legacy_page_flips.push_back(
         HardwareDisplayPlaneList::PageFlipInfo(
             crtc_id, overlay.buffer->GetFramebufferId(), crtc));
   } else {
     plane_list->legacy_page_flips.back().planes.push_back(
         HardwareDisplayPlaneList::PageFlipInfo::Plane(
             hw_plane->plane_id(), overlay.buffer->GetFramebufferId(),
             overlay.display_bounds, src_rect));
   }
   return true;
 }
 
 }  // namespace ui