Mac: Re-initialize the Native Application Menu on run.

This resolves #1511.

widget/cocoa/nsAppShell.mm

@@ -28,6 +28,7 @@
 #include "nsCocoaFeatures.h"
 #include "nsCocoaUtils.h"
 #include "nsChildView.h"
+#include "nsMenuBarX.h"
 #include "nsToolkit.h"
 #include "TextInputHandler.h"
 #include "mozilla/HangMonitor.h"
@@ -647,6 +648,7 @@ nsAppShell::Run(void)
   mStarted = true;
 
   AddScreenWakeLockListener();
+  nsMenuBarX::ResetNativeApplicationMenu();
 
   NS_OBJC_TRY_ABORT([NSApp run]);
 

widget/cocoa/nsMenuBarX.h

@@ -127,6 +127,7 @@ public:
   void              ForceUpdateNativeMenuAt(const nsAString& indexString);
   void              ForceNativeMenuReload(); // used for testing
   static char       GetLocalizedAccelKey(const char *shortcutID);
+  static void       ResetNativeApplicationMenu();
 
 protected:
   void              ConstructNativeMenus();

widget/cocoa/nsMenuBarX.mm

@@ -498,6 +498,14 @@ char nsMenuBarX::GetLocalizedAccelKey(const char *shortcutID)
   return retval;
 }
 
+/* static */
+void nsMenuBarX::ResetNativeApplicationMenu()
+{
+  [sApplicationMenu removeAllItems];
+  [sApplicationMenu release];
+  sApplicationMenu = nil;
+}
+
 // Hide the item in the menu by setting the 'hidden' attribute. Returns it in |outHiddenNode| so
 // the caller can hang onto it if they so choose. It is acceptable to pass nsull
 // for |outHiddenNode| if the caller doesn't care about the hidden node.