Make base::Timer sequence-friendly.

media/base/android/media_codec_loop.cc

Index: media/base/android/media_codec_loop.cc
diff --git a/media/base/android/media_codec_loop.cc b/media/base/android/media_codec_loop.cc
index c6c13cf7c291b9f22191d720fa452e0082f821ab..a3c1edaf8157385b35d6c63c97920c26c4958c8d 100644
--- a/media/base/android/media_codec_loop.cc
+++ b/media/base/android/media_codec_loop.cc
@@ -39,15 +39,15 @@ MediaCodecLoop::MediaCodecLoop(
     int sdk_int,
     Client* client,
     std::unique_ptr<MediaCodecBridge> media_codec,
-    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
+    scoped_refptr<base::SingleThreadTaskRunner> timer_task_runner)
     : state_(STATE_READY),
       client_(client),
       media_codec_(std::move(media_codec)),
       pending_input_buf_index_(kInvalidBufferIndex),
       sdk_int_(sdk_int),
       weak_factory_(this) {
-  if (task_runner)
-    io_timer_.SetTaskRunner(task_runner);
+  if (timer_task_runner)
+    io_timer_.SetTaskRunner(timer_task_runner);
   // TODO(liberato): should this DCHECK?
   if (media_codec_ == nullptr)
     SetState(STATE_ERROR);