Get rid of BookmarkEditor::Show()'s BookmarkEditor::Handler argument.

chrome/browser/cocoa/bookmark_bar_controller.mm

Index: chrome/browser/cocoa/bookmark_bar_controller.mm
diff --git a/chrome/browser/cocoa/bookmark_bar_controller.mm b/chrome/browser/cocoa/bookmark_bar_controller.mm
index 19025d6f881e1387b62aae6a2759db29df4fd02c..1ebe272cf4be1d9a09e6ca105033298951503a5b 100644
--- a/chrome/browser/cocoa/bookmark_bar_controller.mm
+++ b/chrome/browser/cocoa/bookmark_bar_controller.mm
@@ -1254,8 +1254,7 @@ static BOOL ValueInRangeInclusive(CGFloat low, CGFloat value, CGFloat high) {
                        browser_->profile(),
                        node->GetParent(),
                        BookmarkEditor::EditDetails(node),
-                       BookmarkEditor::SHOW_TREE,
-                       nil);
+                       BookmarkEditor::SHOW_TREE);
 }
 
 - (IBAction)cutBookmark:(id)sender {
@@ -1366,8 +1365,7 @@ static BOOL ValueInRangeInclusive(CGFloat low, CGFloat value, CGFloat high) {
                        browser_->profile(),
                        parent,
                        BookmarkEditor::EditDetails(),
-                       BookmarkEditor::SHOW_TREE,
-                       nil);
+                       BookmarkEditor::SHOW_TREE);
 }
 
 // Might be called from the context menu over the bar OR over a