Swap ref_counted.h for scoped_refptr.h when appropriate in //media.

At some point, scoped_refptr got split off into its own header. Use it
in //media headers when appropriate and then add includes to fix the
build.

Bug: 1381627
Change-Id: I1b3ef608b6ab1084f242cf176f19935f1e2843c1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4005370
Reviewed-by: Matthew Wolenetz <wolenetz@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Alex Gough <ajgo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1068212}

diff --git a/media/renderers/renderer_impl.h b/media/renderers/renderer_impl.h
index 0e30262..3a0d09b 100644
--- a/media/renderers/renderer_impl.h
+++ b/media/renderers/renderer_impl.h

@@ -10,7 +10,7 @@
 
 #include "base/cancelable_callback.h"
 #include "base/memory/raw_ptr.h"
-#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_refptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/task/sequenced_task_runner.h"