[chromecast] Fix build with enable_mojo_media=true.

chromecast/browser/media/media_pipeline_host.cc

Index: chromecast/browser/media/media_pipeline_host.cc
diff --git a/chromecast/browser/media/media_pipeline_host.cc b/chromecast/browser/media/media_pipeline_host.cc
index 5b35063ef6dd83f9b2e4c5315b2618d6482468b9..34209da6fa6f31abaa12063b1539c48c9f41b18e 100644
--- a/chromecast/browser/media/media_pipeline_host.cc
+++ b/chromecast/browser/media/media_pipeline_host.cc
@@ -55,9 +55,10 @@ MediaPipelineHost::~MediaPipelineHost() {
   media_track_map_.clear();
 }
 
-void MediaPipelineHost::Initialize(LoadType load_type,
-                                   const MediaPipelineClient& client,
-                                   const CreateBackendCB& create_backend_cb) {
+void MediaPipelineHost::Initialize(
+    LoadType load_type,
+    const MediaPipelineClient& client,
+    const CreateMediaPipelineBackendCB& create_backend_cb) {
   DCHECK(thread_checker_.CalledOnValidThread());
   media_pipeline_.reset(new MediaPipelineImpl());
   task_runner_.reset(new TaskRunnerImpl());