Fix typo in AudioStreamIndicator causing hangs

chrome/browser/media/audio_stream_indicator.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/media/audio_stream_indicator.h"
 
 #include "base/bind.h"
 #include "chrome/browser/tab_contents/tab_util.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/invalidate_type.h"
@@ skipping 46 matching lines @@
     int render_view_id,
     int stream_id,
     bool playing) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   RenderViewId id(render_process_id, render_view_id);
   if (playing) {
     audio_streams_[id].insert(stream_id);
   } else {
     std::map<RenderViewId, std::set<int> >::iterator it =
         audio_streams_.find(id);
-    if (it != audio_streams_.end())
+    if (it == audio_streams_.end())
       return;
 
     it->second.erase(stream_id);
     if (it->second.empty())
       audio_streams_.erase(it);
   }
 
   WebContents* web_contents = tab_util::GetWebContentsByID(render_process_id,
                                                            render_view_id);
   if (web_contents)
     web_contents->NotifyNavigationStateChanged(content::INVALIDATE_TYPE_TAB);
 }