Revert of Pass task runners to AudioManager constructor.

components/audio_modem/audio_player_impl.cc

Index: components/audio_modem/audio_player_impl.cc
diff --git a/components/audio_modem/audio_player_impl.cc b/components/audio_modem/audio_player_impl.cc
index 2a02f5aa6ef9fd8ac1e1c3e86e62e2c7e13ca023..cd52f05485ab4bd87a6daae246eff38ffaef85b2 100644
--- a/components/audio_modem/audio_player_impl.cc
+++ b/components/audio_modem/audio_player_impl.cc
@@ -8,9 +8,11 @@
 #include <string>
 
 #include "base/bind.h"
-#include "base/location.h"
+#include "base/bind_helpers.h"
 #include "base/logging.h"
+#include "base/run_loop.h"
 #include "components/audio_modem/public/audio_modem_types.h"
+#include "content/public/browser/browser_thread.h"
 #include "media/audio/audio_manager.h"
 #include "media/audio/audio_parameters.h"
 #include "media/base/audio_bus.h"
@@ -160,4 +162,19 @@
                  base::Unretained(this)));
 }
 
+void AudioPlayerImpl::FlushAudioLoopForTesting() {
+  if (media::AudioManager::Get()->GetTaskRunner()->BelongsToCurrentThread())
+    return;
+
+  // Queue task on the audio thread, when it is executed, that means we've
+  // successfully executed all the tasks before us.
+  base::RunLoop rl;
+  media::AudioManager::Get()->GetTaskRunner()->PostTaskAndReply(
+      FROM_HERE,
+      base::Bind(base::IgnoreResult(&AudioPlayerImpl::FlushAudioLoopForTesting),
+                 base::Unretained(this)),
+      rl.QuitClosure());
+  rl.Run();
+}
+
 }  // namespace audio_modem