Tracks all open input streams in AudioManagerBase.

media/audio/mac/audio_manager_mac.cc

Index: media/audio/mac/audio_manager_mac.cc
diff --git a/media/audio/mac/audio_manager_mac.cc b/media/audio/mac/audio_manager_mac.cc
index f59e9d4da4bfa90d9696b0a9b882a6d06a3952b1..b9d059e01f4642cae6929c17c52e461c8539ecfc 100644
--- a/media/audio/mac/audio_manager_mac.cc
+++ b/media/audio/mac/audio_manager_mac.cc
@@ -384,6 +384,7 @@ AudioManagerMac::~AudioManagerMac() {
   // and IncreaseIOBufferSizeIfPossible() which both touches native Core Audio
   // APIs and they can fail and disrupt tests during shutdown.
   in_shutdown_ = true;
+  Shutdown();

[alokp, 2016/11/15 14:29:38]

Moved here so that proxy streams are closed before the real ones. The proxy ones
may be holding references to real streams.

   // We have seen cases where active input audio is not closed down properly
   // at browser shutdown. AudioInputController::Close() is called but tasks
   // in AudioInputController::DoClose() are not executed. Hence, input streams
@@ -412,7 +413,6 @@ AudioManagerMac::~AudioManagerMac() {
     // Avoids hitting CHECK in dtor of AudioManagerBase.
     stream->Close();
   }
-  Shutdown();
 }
 
 bool AudioManagerMac::HasAudioOutputDevices() {