Explicitly use Cmd+w for "Close Window" in apps. (Mac)

Previously, the "Close Window" item is copied from Chrome's "File" menu.
However, the key equivalent of this item changes between Cmd+Shift+w and
Cmd+w depending on whether a tabbed window has focus. This happens in
-[AppControllerMac adjustCloseWindowMenuItemKeyEquivalent:].

This causes a bug when the item in the app's menu does not match the one
in Chrome's. OSX will remove the keyboard shortcut for any items that have
a matching title but different key equivalents. 

In this CL, the key equivalent is always set to Cmd+w in the app's menu. The "Close Window" item in Chrome will be changed to Cmd+w when an app
window gains focus. Duplicate items are allowed to share a key equivalent
if their titles match.

BUG=302117

Review URL: https://codereview.chromium.org/130673002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244133 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/cocoa/apps/app_shim_menu_controller_mac.mm

@@ -237,6 +237,12 @@ void AddDuplicateItem(NSMenuItem* top_level_item,
   [[fileMenuItem_ submenu] addItem:[openDoppelganger_ menuItem]];
   [[fileMenuItem_ submenu] addItem:[NSMenuItem separatorItem]];
   AddDuplicateItem(fileMenuItem_, IDC_FILE_MENU, IDC_CLOSE_WINDOW);
+  // Set the expected key equivalent explicitly here because
+  // -[AppControllerMac adjustCloseWindowMenuItemKeyEquivalent:] sets it to
+  // "W" (Cmd+Shift+w) when a tabbed window has focus; it will change it back
+  // to Cmd+w when a non-tabbed window has focus.
+  [[[fileMenuItem_ submenu] itemWithTag:IDC_CLOSE_WINDOW]
+      setKeyEquivalent:@"w"];
 
   // Edit menu. This copies the menu entirely and removes
   // "Paste and Match Style" and "Find". This is because the last two items,