Remove the AudioManager singleton.

content/browser/resource_context.cc

Index: content/browser/resource_context.cc
===================================================================
--- content/browser/resource_context.cc	(revision 113173)
+++ content/browser/resource_context.cc	(working copy)
@@ -21,7 +21,9 @@
       quota_manager_(NULL),
       host_zoom_map_(NULL),
       media_observer_(NULL),
-      media_stream_manager_(NULL) {
+      download_id_factory_(NULL),
+      media_stream_manager_(NULL),
+      audio_manager_(NULL) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 }
 
@@ -158,6 +160,7 @@
   EnsureInitialized();
   return download_id_factory_;
 }
+
 void ResourceContext::set_download_id_factory(
     DownloadIdFactory* download_id_factory) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
@@ -177,4 +180,18 @@
   media_stream_manager_ = media_stream_manager;
 }
 
+AudioManager* ResourceContext::audio_manager() const {
+  // The AudioManager isn't necessarily initialized with other
+  // resource context variables, so if we already have one, we can still
+  // delay initializing the other ones.
+  if (!audio_manager_)
+    EnsureInitialized();
+  return audio_manager_;
+}
+
+void ResourceContext::set_audio_manager(AudioManager* audio_manager) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  audio_manager_ = audio_manager;
+}
+
 }  // namespace content