ozone: Fix HardwareDisplayController::AddCrtc.

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

Index: ui/ozone/platform/drm/gpu/hardware_display_controller.cc
diff --git a/ui/ozone/platform/drm/gpu/hardware_display_controller.cc b/ui/ozone/platform/drm/gpu/hardware_display_controller.cc
index ec411f4fcad5aafdf1cd1423556d0a26b377caf9..82c927d97eae0dc3d9b875d06a233ed2865545a7 100644
--- a/ui/ozone/platform/drm/gpu/hardware_display_controller.cc
+++ b/ui/ozone/platform/drm/gpu/hardware_display_controller.cc
@@ -202,14 +202,16 @@ bool HardwareDisplayController::MoveCursor(const gfx::Point& location) {
 void HardwareDisplayController::AddCrtc(
     std::unique_ptr<CrtcController> controller) {
   scoped_refptr<DrmDevice> drm = controller->drm();
-  owned_hardware_planes_[drm.get()] =
-      base::MakeUnique<HardwareDisplayPlaneList>();
+
+  std::unique_ptr<HardwareDisplayPlaneList>& owned_planes =
+      owned_hardware_planes_[drm.get()];
+  if (!owned_planes)
+    owned_planes.reset(new HardwareDisplayPlaneList());
 
   // Check if this controller owns any planes and ensure we keep track of them.
   const std::vector<std::unique_ptr<HardwareDisplayPlane>>& all_planes =
       drm->plane_manager()->planes();
-  HardwareDisplayPlaneList* crtc_plane_list =
-      owned_hardware_planes_[drm.get()].get();
+  HardwareDisplayPlaneList* crtc_plane_list = owned_planes.get();
   uint32_t crtc = controller->crtc();
   for (const auto& plane : all_planes) {
     if (plane->in_use() && (plane->owning_crtc() == crtc))