[Mac] Refactor bookmark bar controller

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

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <cmath>
 
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model_factory.h"
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_bar_constants.h"
@@ skipping 772 matching lines @@
   ASSERT_TRUE(targetButton);
   [folderController dragButton:draggedButton
                             to:[targetButton center]
                           copy:NO];
   // The button should have landed just after "2f1b".
   const std::string expected_string("2f:[ 2f1b 1b 2f2f:[ 2f2f1b "
       "2f2f2b 2f2f3b ] 2f3b ] 3b 4f:[ 4f1f:[ 4f1f1b 4f1f2b 4f1f3b ] 4f2f:[ "
       "4f2f1b 4f2f2b 4f2f3b ] 4f3f:[ 4f3f1b 4f3f2b 4f3f3b ] ] 5b ");
   EXPECT_EQ(expected_string, bookmarks::test::ModelStringFromNode(root));
 
-  // Verify the window still appears by looking for its controller.
+  // Reopen the window.
+  [[toFolder target] performSelector:@selector(openBookmarkFolderFromButton:)
+                          withObject:toFolder];
   EXPECT_TRUE([bar_ folderController]);
+  folderController = [bar_ folderController];
 
   // Gather the new frames.
   NSRect newToFolderFrame = [toFolder frame];
   NSRect newToWindowFrame = [toWindow frame];
   // The toFolder should have shifted left horizontally but not vertically.
   NSRect expectedToFolderFrame =
       NSOffsetRect(oldToFolderFrame, -horizontalShift, 0);
   EXPECT_NSRECT_EQ(expectedToFolderFrame, newToFolderFrame);
   // The toWindow should have shifted left horizontally, down vertically,
   // and grown vertically.
@@ skipping 919 matching lines @@
   DeleteBookmark([folder parentButton], profile());
   EXPECT_FALSE([folder folderController]);
 }
 
 // TODO(jrg): draggingEntered: and draggingExited: trigger timers so
 // they are hard to test.  Factor out "fire timers" into routines
 // which can be overridden to fire immediately to make behavior
 // confirmable.
 // There is a similar problem with mouseEnteredButton: and
 // mouseExitedButton:.