Fix use after free for cached_displays_.

ui/ozone/platform/drm/host/drm_native_display_delegate.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_HOST_DRM_NATIVE_DISPLAY_DELEGATE_H_
 #define UI_OZONE_PLATFORM_DRM_HOST_DRM_NATIVE_DISPLAY_DELEGATE_H_
 
 #include <stdint.h>
 
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "ui/display/types/native_display_delegate.h"
 
 namespace ui {
 
 class DrmDisplayHostManager;
 
 class DrmNativeDisplayDelegate : public NativeDisplayDelegate {
  public:
   DrmNativeDisplayDelegate(DrmDisplayHostManager* display_manager);
   ~DrmNativeDisplayDelegate() override;
 
   void OnConfigurationChanged();
+  void OnDisplaySnapshotsInvalidated();
 
   // NativeDisplayDelegate overrides:
   void Initialize() override;
   void GrabServer() override;
   void UngrabServer() override;
   void TakeDisplayControl(const DisplayControlCallback& callback) override;
   void RelinquishDisplayControl(
       const DisplayControlCallback& callback) override;
   void SyncWithServer() override;
   void SetBackgroundColor(uint32_t color_argb) override;
@@ skipping 29 matching lines @@
   DrmDisplayHostManager* display_manager_;  // Not owned.
 
   base::ObserverList<NativeDisplayObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(DrmNativeDisplayDelegate);
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_DRM_HOST_DRM_NATIVE_DISPLAY_DELEGATE_H_