[Mac] Show context menu on empty BMB item.

chrome/browser/ui/cocoa/bookmarks/bookmark_context_menu_cocoa_controller.mm

Index: chrome/browser/ui/cocoa/bookmarks/bookmark_context_menu_cocoa_controller.mm
===================================================================
--- chrome/browser/ui/cocoa/bookmarks/bookmark_context_menu_cocoa_controller.mm	(revision 222257)
+++ chrome/browser/ui/cocoa/bookmarks/bookmark_context_menu_cocoa_controller.mm	(working copy)
@@ -62,12 +62,12 @@
   if (bookmarkNode_ == bookmarkModel->other_node()) {
     nodes.push_back(bookmarkNode_);
     parent = bookmarkModel->bookmark_bar_node();
-  } else if (bookmarkNode_ != bookmarkModel->bookmark_bar_node()) {
+  } else if (bookmarkNode_ == bookmarkModel->bookmark_bar_node()) {
+    parent = bookmarkModel->bookmark_bar_node();
+    nodes.push_back(parent);
+  } else if (bookmarkNode_) {
     nodes.push_back(bookmarkNode_);
     parent = bookmarkNode_->parent();
-  } else {
-    parent = bookmarkModel->bookmark_bar_node();
-    nodes.push_back(parent);
   }
 
   Browser* browser = [bookmarkBarController_ browser];
@@ -82,21 +82,23 @@
                                        useWithPopUpButtonCell:NO]);
 }
 
-- (NSMenu*)menuForBookmarkNode:(const BookmarkNode*)node {
+- (BookmarkModel*)bookmarkModel {
   // Depending on timing, the model may not yet have been loaded.
   BookmarkModel* bookmarkModel = [bookmarkBarController_ bookmarkModel];
   if (!bookmarkModel || !bookmarkModel->loaded())
     return nil;
+  return bookmarkModel;
+}
 
+- (NSMenu*)menuForBookmarkNode:(const BookmarkNode*)node {
+  BookmarkModel* bookmarkModel = [self bookmarkModel];
+
   // This may be called before the BMB view has been added to the window. In
   // that case, simply return nil so that BookmarkContextMenuController doesn't
   // get created with a nil window.
-  if (![bookmarkBarController_ browserWindow])
+  if (!bookmarkModel || ![bookmarkBarController_ browserWindow])
     return nil;
 
-  if (!node)
-    node = bookmarkModel->bookmark_bar_node();
-
   // Rebuild the menu if it's for a different node than the last request.
   if (!menuController_ || node != bookmarkNode_) {
     bookmarkNode_ = node;
@@ -105,6 +107,14 @@
   return [menuController_ menu];
 }
 
+- (NSMenu*)menuForBookmarkBar {
+  BookmarkModel* bookmarkModel = [self bookmarkModel];
+  if (!bookmarkModel)
+    return nil;
+
+  return [self menuForBookmarkNode:bookmarkModel->bookmark_bar_node()];
+}
+
 - (void)willExecuteCommand:(int)command {
   // Some items should not close currently-open sub-folder menus.
   switch (command) {