ozone: Fix HardwareDisplayController::AddCrtc.

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 184 matching lines @@
   bool status = true;
   for (const auto& controller : crtc_controllers_)
     status &= controller->MoveCursor(location);
 
   return status;
 }
 
 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))
       crtc_plane_list->old_plane_list.push_back(plane.get());
   }
 
   crtc_controllers_.push_back(std::move(controller));
 }
 
 std::unique_ptr<CrtcController> HardwareDisplayController::RemoveCrtc(
@@ skipping 70 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