Optimize plane usage when primary is obscured by Overlay

ui/ozone/platform/drm/gpu/hardware_display_plane_manager.h

 // 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.
 
 #ifndef UI_OZONE_PLATFORM_DRM_GPU_HARDWARE_DISPLAY_PLANE_MANAGER_H_
 #define UI_OZONE_PLATFORM_DRM_GPU_HARDWARE_DISPLAY_PLANE_MANAGER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 #include <xf86drmMode.h>
@@ skipping 105 matching lines @@
 
   // Convert |crtc_id| into an index, returning -1 if the ID couldn't be found.
   int LookupCrtcIndex(uint32_t crtc_id) const;
 
   // Returns true if |plane| can support |overlay| and compatible with
   // |crtc_index|.
   bool IsCompatible(HardwareDisplayPlane* plane,
                     const OverlayPlane& overlay,
                     uint32_t crtc_index) const;
 
+  void ResetCurrentPlaneList(HardwareDisplayPlaneList* plane_list) const;
+
   // Object containing the connection to the graphics device and wraps the API
   // calls to control it. Not owned.
   DrmDevice* drm_;
 
   ScopedVector<HardwareDisplayPlane> planes_;
   std::vector<uint32_t> crtcs_;
 
   DISALLOW_COPY_AND_ASSIGN(HardwareDisplayPlaneManager);
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_DRM_GPU_HARDWARE_DISPLAY_PLANE_MANAGER_H_