Candidate fix for a crash at shutdown when the IO thread is going away. More details in the bug rep…

content/renderer/media/audio_input_message_filter.cc

Index: content/renderer/media/audio_input_message_filter.cc
diff --git a/content/renderer/media/audio_input_message_filter.cc b/content/renderer/media/audio_input_message_filter.cc
index b523ac6d9ce398f0a99f1dd0fd8c9ee5d1804705..850cd1a0fa57c49bf06deb2a41c32a654df4f773 100644
--- a/content/renderer/media/audio_input_message_filter.cc
+++ b/content/renderer/media/audio_input_message_filter.cc
@@ -22,6 +22,11 @@ AudioInputMessageFilter::AudioInputMessageFilter()
 
 AudioInputMessageFilter::~AudioInputMessageFilter() {
   DVLOG(1) << "AudioInputMessageFilter::~AudioInputMessageFilter()";
+
+  // Just in case the message filter is deleted before the channel
+  // is closed and there are still living audio devices.
+  OnChannelClosing();
+
   DCHECK_EQ(filter_, this);
   filter_ = NULL;
 }
@@ -83,6 +88,7 @@ void AudioInputMessageFilter::OnChannelClosing() {
   IDMap<media::AudioInputIPCDelegate>::iterator it(&delegates_);
   while (!it.IsAtEnd()) {
     it.GetCurrentValue()->OnIPCClosed();
+    delegates_.Remove(it.GetCurrentKey());
     it.Advance();
   }
 }