ozone: drm: Fix graphics buffer handle leak in DrmConsoleBuffer

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

Index: ui/ozone/platform/drm/test/mock_drm_device.cc
diff --git a/ui/ozone/platform/drm/test/mock_drm_device.cc b/ui/ozone/platform/drm/test/mock_drm_device.cc
index 6af2c04bac8481796cc9d9eb4a3e05366d9941b9..eb116239f59b0410330eb1db78b61729d91b48f2 100644
--- a/ui/ozone/platform/drm/test/mock_drm_device.cc
+++ b/ui/ozone/platform/drm/test/mock_drm_device.cc
@@ -219,6 +219,10 @@ void MockDrmDevice::DestroyDumbBuffer(const SkImageInfo& info,
   delete[] static_cast<char*>(pixels);
 }
 
+bool MockDrmDevice::CloseBufferHandle(uint32_t handle) {
+  return true;
+}
+
 bool MockDrmDevice::CommitProperties(drmModePropertySet* properties,
                                      uint32_t flags,
                                      const PageFlipCallback& callback) {