add pythor_xla support for render a video (#10443)

* Update rerender_a_video.py

* Update rerender_a_video.py

* make style

---------
Co-authored-by: hlky <hlky@hlky.ac>

examples/community/rerender_a_video.py

@@ -30,10 +30,17 @@ from diffusers.pipelines.controlnet.multicontrolnet import MultiControlNetModel
 from diffusers.pipelines.controlnet.pipeline_controlnet_img2img import StableDiffusionControlNetImg2ImgPipeline
 from diffusers.pipelines.stable_diffusion.safety_checker import StableDiffusionSafetyChecker
 from diffusers.schedulers import KarrasDiffusionSchedulers
-from diffusers.utils import BaseOutput, deprecate, logging
+from diffusers.utils import BaseOutput, deprecate, is_torch_xla_available, logging
 from diffusers.utils.torch_utils import is_compiled_module, randn_tensor
 
 
+if is_torch_xla_available():
+    import torch_xla.core.xla_model as xm
+
+    XLA_AVAILABLE = True
+else:
+    XLA_AVAILABLE = False
+
 logger = logging.get_logger(__name__)  # pylint: disable=invalid-name
 
 
@@ -1100,6 +1107,9 @@ class RerenderAVideoPipeline(StableDiffusionControlNetImg2ImgPipeline):
                             if callback is not None and i % callback_steps == 0:
                                 callback(i, t, latents)
 
+                        if XLA_AVAILABLE:
+                            xm.mark_step()
+
                     return latents
 
             if mask_start_t <= mask_end_t: