[Mac] Inform reference counted objects that hold a weak Browser* when the Browser is being destroye…

chrome/browser/ui/cocoa/toolbar/back_forward_menu_controller.mm

Index: chrome/browser/ui/cocoa/toolbar/back_forward_menu_controller.mm
diff --git a/chrome/browser/ui/cocoa/toolbar/back_forward_menu_controller.mm b/chrome/browser/ui/cocoa/toolbar/back_forward_menu_controller.mm
index c7e2b0f3429e37553347bebc49bc6c3f343ae6f4..e43ba9e536d5368c7bb1f18f21d4a90800aed0c1 100644
--- a/chrome/browser/ui/cocoa/toolbar/back_forward_menu_controller.mm
+++ b/chrome/browser/ui/cocoa/toolbar/back_forward_menu_controller.mm
@@ -40,6 +40,13 @@ using base::SysUTF16ToNSString;
   return self;
 }
 
+- (void)browserWillBeDestroyed {
+  [button_ setAttachedMenu:nullptr];

[tapted, 2015/07/07 04:25:59]

nit: nullptr -> nil

[jackhou1, 2015/07/07 08:33:06]

Done.

+  [backForwardMenu_ setDelegate:nil];
+  backForwardMenu_.reset();
+  model_.reset();
+}
+
 // Methods as delegate:
 
 // Called by backForwardMenu_ just before tracking begins.