Revert r95841 due to failing media_unittests on linux_shared bot.

media/audio/audio_manager_base.h

Index: media/audio/audio_manager_base.h
===================================================================
--- media/audio/audio_manager_base.h	(revision 95843)
+++ media/audio/audio_manager_base.h	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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.
 
@@ -13,7 +13,7 @@
 class AudioOutputDispatcher;
 
 // AudioManagerBase provides AudioManager functions common for all platforms.
-class MEDIA_EXPORT AudioManagerBase : public AudioManager {
+class AudioManagerBase : public AudioManager {
  public:
   // Name of the generic "default" device.
   static const char kDefaultDeviceName[];