Disable mute/unmute when media does not have an audio track.

chrome/common/render_messages.h

 // Copyright (c) 2006-2009 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.
 
 #ifndef CHROME_COMMON_RENDER_MESSAGES_H_
 #define CHROME_COMMON_RENDER_MESSAGES_H_
 
 #include <string>
 #include <vector>
 #include <map>
@@ skipping 861 matching lines @@
     LogParam(p.http_status_code, l);
     l->append(L")");
   }
 };
 
 template <>
 struct ParamTraits<ContextMenuMediaParams> {
   typedef ContextMenuMediaParams param_type;
   static void Write(Message* m, const param_type& p) {
     WriteParam(m, p.player_state);
+    WriteParam(m, p.has_audio);
   }
   static bool Read(const Message* m, void** iter, param_type* p) {
     return
-      ReadParam(m, iter, &p->player_state);
+      ReadParam(m, iter, &p->player_state) &&
+      ReadParam(m, iter, &p->has_audio);
   }
 };
 
 template <>
 struct ParamTraits<ContextMenuParams> {
   typedef ContextMenuParams param_type;
   static void Write(Message* m, const param_type& p) {
     WriteParam(m, p.node_type);
     WriteParam(m, p.x);
     WriteParam(m, p.y);
@@ skipping 1143 matching lines @@
   }
 };
 
 }  // namespace IPC
 
 
 #define MESSAGES_INTERNAL_FILE "chrome/common/render_messages_internal.h"
 #include "ipc/ipc_message_macros.h"
 
 #endif  // CHROME_COMMON_RENDER_MESSAGES_H_