cocoa: add some tab-manipulation menu items

chrome/browser/ui/tabs/tab_strip_model.cc

Index: chrome/browser/ui/tabs/tab_strip_model.cc
diff --git a/chrome/browser/ui/tabs/tab_strip_model.cc b/chrome/browser/ui/tabs/tab_strip_model.cc
index 98f12a0360f13128708b16566147ceae49a0c4f6..9905fca7cbd05501a15c137b5a2689499591e083 100644
--- a/chrome/browser/ui/tabs/tab_strip_model.cc
+++ b/chrome/browser/ui/tabs/tab_strip_model.cc
@@ -985,7 +985,7 @@ void TabStripModel::ExecuteContextMenuCommand(
 
     case CommandToggleTabAudioMuted: {
       const std::vector<int>& indices = GetIndicesForCommand(context_index);
-      const bool mute = !chrome::AreAllTabsMuted(*this, indices);
+      const bool mute = WillContextMenuMute(context_index);
       if (mute)
         base::RecordAction(UserMetricsAction("TabContextMenu_MuteTabs"));
       else
@@ -1046,6 +1046,11 @@ std::vector<int> TabStripModel::GetIndicesClosedByCommand(
   return indices;
 }
 
+bool TabStripModel::WillContextMenuMute(int index) {
+  std::vector<int> indices = GetIndicesForCommand(index);
+  return !chrome::AreAllTabsMuted(*this, indices);
+}
+
 bool TabStripModel::WillContextMenuPin(int index) {
   std::vector<int> indices = GetIndicesForCommand(index);
   // If all tabs are pinned, then we unpin, otherwise we pin.