Add audio playback (all platforms) to cast_receiver_app.

chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc

Index: chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc
diff --git a/chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc b/chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc
index 57a1e4806832312d385aaf65bcfb7c9bdea0f70c..3568e16f42a888cab519909519e65aad5be4dff9 100644
--- a/chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc
+++ b/chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc
@@ -336,9 +336,7 @@ IN_PROC_BROWSER_TEST_F(CastStreamingApiTestWithPixelOutput, DISABLED_EndToEnd) {
   receiver->WaitForColorAndTone(kGreenInYUV, 500 /* Hz */, kOneHalfSecond);
   receiver->WaitForColorAndTone(kBlueInYUV, 1800 /* Hz */, kOneHalfSecond);
 
-  // TODO(miu): Uncomment once GetWeakPtr() NULL crash in PacedSender is fixed
-  // (see http://crbug.com/349786):
-  // receiver->DestroySoon();
+  receiver->Stop();
   cast_environment->Shutdown();
 }