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

chrome/browser/tab_contents/render_view_context_menu.cc

 // 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.
 
 #include "chrome/browser/tab_contents/render_view_context_menu.h"
 
 #include "app/l10n_util.h"
 #include "base/clipboard.h"
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 299 matching lines @@
       return true;
 
     case IDS_CONTENT_CONTEXT_FULLSCREEN:
       // TODO(ajwong): Enable fullscreen after we actually implement this.
       return false;
 
     // Media control commands should all be disabled if the player is in an
     // error state.
     case IDS_CONTENT_CONTEXT_PLAY:
     case IDS_CONTENT_CONTEXT_PAUSE:
+    case IDS_CONTENT_CONTEXT_LOOP:
+      return (params_.media_params.player_state &
+              ContextMenuMediaParams::IN_ERROR) == 0;
+
+    // Mute and unmute should also be disabled if the player has no audio.
     case IDS_CONTENT_CONTEXT_MUTE:
     case IDS_CONTENT_CONTEXT_UNMUTE:
-    case IDS_CONTENT_CONTEXT_LOOP:
-      return (params_.media_params.player_state &
+      return params_.media_params.has_audio &&
+             (params_.media_params.player_state &
               ContextMenuMediaParams::IN_ERROR) == 0;
 
     case IDS_CONTENT_CONTEXT_SAVESCREENSHOTAS:
       // TODO(ajwong): Enable save screenshot after we actually implement
       // this.
       return false;
 
     case IDS_CONTENT_CONTEXT_COPYAUDIOLOCATION:
     case IDS_CONTENT_CONTEXT_COPYVIDEOLOCATION:
     case IDS_CONTENT_CONTEXT_COPYIMAGELOCATION:
@@ skipping 440 matching lines @@
   WriteTextToClipboard(UTF8ToUTF16(utf8_text));
   DidWriteURLToClipboard(utf8_text);
 }
 
 void RenderViewContextMenu::MediaPlayerActionAt(
     int x,
     int y,
     const MediaPlayerAction& action) {
   source_tab_contents_->render_view_host()->MediaPlayerActionAt(x, y, action);
 }