Remove all remaining traces of MessageLoopProxy.

chromecast/renderer/media/chromecast_media_renderer_factory.cc

Index: chromecast/renderer/media/chromecast_media_renderer_factory.cc
diff --git a/chromecast/renderer/media/chromecast_media_renderer_factory.cc b/chromecast/renderer/media/chromecast_media_renderer_factory.cc
index 817e9d5bdf4381f3aa91288336505cbe8ee7dd60..4ac9da94023fdcc114792685801ecd3aa2c01ccb 100644
--- a/chromecast/renderer/media/chromecast_media_renderer_factory.cc
+++ b/chromecast/renderer/media/chromecast_media_renderer_factory.cc
@@ -32,7 +32,7 @@ ChromecastMediaRendererFactory::CreateRenderer(
   // TODO(erickung): crbug.com/443956. Need to provide right LoadType.
   LoadType cma_load_type = kLoadTypeMediaSource;
   std::unique_ptr<MediaPipelineProxy> cma_media_pipeline(new MediaPipelineProxy(
-      render_frame_id_, content::RenderThread::Get()->GetIOMessageLoopProxy(),
+      render_frame_id_, content::RenderThread::Get()->GetIOTaskRunner(),
       cma_load_type));
   std::unique_ptr<CmaRenderer> cma_renderer(new CmaRenderer(
       std::move(cma_media_pipeline), video_renderer_sink, gpu_factories_));