[Merge to 2883] Revert "[scheduler] Teach scheduler about audio state"

content/common/page_messages.h

 // Copyright 2016 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 "content/common/page_message_enums.h"
 #include "ipc/ipc_message_macros.h"
 #include "ui/gfx/geometry/rect.h"
 
 // IPC messages for page-level actions.
 // Multiply-included message file, hence no include guard.
@@ skipping 25 matching lines @@
 // Informs the renderer that the page is no longer hidden.
 IPC_MESSAGE_ROUTED0(PageMsg_WasShown)
 
 // Sent when the history for this page is altered from another process. The
 // history list should be reset to |history_length| length, and the offset
 // should be reset to |history_offset|.
 IPC_MESSAGE_ROUTED2(PageMsg_SetHistoryOffsetAndLength,
                     int /* history_offset */,
                     int /* history_length */)
 
-IPC_MESSAGE_ROUTED1(PageMsg_AudioStateChanged, bool /* is_audio_playing */)
-
 // -----------------------------------------------------------------------------
 // Messages sent from the renderer to the browser.
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent PageMsg, then ifdefs for platform specific PageMsg, then platform
 // independent PageHostMsg, then ifdefs for platform specific PageHostMsg.