ozone: drm: Fix graphics buffer handle leak in DrmConsoleBuffer

ui/ozone/platform/drm/test/mock_drm_device.h

Index: ui/ozone/platform/drm/test/mock_drm_device.h
diff --git a/ui/ozone/platform/drm/test/mock_drm_device.h b/ui/ozone/platform/drm/test/mock_drm_device.h
index 7745a05df8d5d688a02ea8a724fbf9913ad25a69..41d5ba35e8946e2c8822ea946642f8a67803494d 100644
--- a/ui/ozone/platform/drm/test/mock_drm_device.h
+++ b/ui/ozone/platform/drm/test/mock_drm_device.h
@@ -106,6 +106,8 @@ class MockDrmDevice : public ui::DrmDevice {
                          uint32_t handle,
                          uint32_t stride,
                          void* pixels) override;
+
+  bool CloseBufferHandle(uint32_t handle) override;
   bool CommitProperties(drmModePropertySet* properties,
                         uint32_t flags,
                         const PageFlipCallback& callback) override;