[Mac] Fix "empty" item position when BMB folder becomes empty.

chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_controller.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.
 
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_controller.h"
 
 #include "base/mac/bundle_locations.h"
 #include "base/mac/mac_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
@@ skipping 90 matching lines @@
     deltaVisibleY(0.0),
     deltaScrollerHeight(0.0),
     deltaScrollerY(0.0),
     minimumY(0.0),
     screenBottomY(0.0),
     oldWindowY(0.0),
     folderY(0.0),
     folderTop(0.0) {}
 };
 
+NSRect GetFirstButtonFrameForHeight(CGFloat height) {
+  CGFloat y = height - bookmarks::kBookmarkFolderButtonHeight -
+      bookmarks::kBookmarkVerticalPadding;
+  return NSMakeRect(0, y, bookmarks::kDefaultBookmarkWidth,
+                    bookmarks::kBookmarkFolderButtonHeight);
+}
+
 }  // namespace
 
 
 // Required to set the right tracking bounds for our fake menus.
 @interface NSView(Private)
 - (void)_updateTrackingAreas;
 @end
 
 @interface BookmarkBarFolderController(Private)
 - (void)configureWindow;
@@ skipping 658 matching lines @@
   // Must have at least 1 button (for "empty")
   int buttons = std::max(node->child_count() - startingIndex, 1);
 
   // Prelim height of the window.  We'll trim later as needed.
   int height = [self menuHeightForButtonCount:buttons];
   // We'll need this soon...
   [self window];
 
   // TODO(jrg): combine with frame code in bookmark_bar_controller.mm
   // http://crbug.com/35966
-  NSRect buttonsOuterFrame = NSMakeRect(
-      0,
-      height - bookmarks::kBookmarkFolderButtonHeight -
-          bookmarks::kBookmarkVerticalPadding,
-      bookmarks::kDefaultBookmarkWidth,
-      bookmarks::kBookmarkFolderButtonHeight);
+  NSRect buttonsOuterFrame = GetFirstButtonFrameForHeight(height);
 
   // TODO(jrg): combine with addNodesToButtonList: code from
   // bookmark_bar_controller.mm (but use y offset)
   // http://crbug.com/35966
   if (node->empty()) {
     // If no children we are the empty button.
     BookmarkButton* button = [self makeButtonForNode:nil
                                                frame:buttonsOuterFrame];
     [buttons_ addObject:button];
     [folderView_ addSubview:button];
@@ skipping 1105 matching lines @@
     for (NSButton* aButton in buttons_.get()) {
       // If this button is showing its menu then we need to move the menu, too.
       if (aButton == subButton)
         [folderController_
             offsetFolderMenuWindow:NSMakeSize(0.0, chrome::kBookmarkBarHeight)];
     }
   } else {
     // If all nodes have been removed from this folder then add in the
     // 'empty' placeholder button.
     NSRect buttonFrame =
-        NSMakeRect(0.0, 0.0, bookmarks::kDefaultBookmarkWidth,
-                   bookmarks::kBookmarkFolderButtonHeight);
+        GetFirstButtonFrameForHeight([self menuHeightForButtonCount:1]);
     BookmarkButton* button = [self makeButtonForNode:nil
                                                frame:buttonFrame];
     [buttons_ addObject:button];
     [folderView_ addSubview:button];
     buttonCount = 1;
   }
 
   [self adjustWindowForButtonCount:buttonCount];
 
   if (animate && !ignoreAnimations_)
@@ skipping 38 matching lines @@
 
 - (void)setIgnoreAnimations:(BOOL)ignore {
   ignoreAnimations_ = ignore;
 }
 
 - (BookmarkButton*)buttonThatMouseIsIn {
   return buttonThatMouseIsIn_;
 }
 
 @end  // BookmarkBarFolderController