Address clang complaint about possible unrecognized function call....

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

 // Copyright (c) 2010 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/mac_util.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/bookmarks/bookmark_utils.h"
@@ skipping 1644 matching lines @@
 }
 
 - (CGFloat)verticalScrollArrowHeight {
   return verticalScrollArrowHeight_;
 }
 
 - (NSView*)visibleView {
   return visibleView_;
 }
 
-- (NSView*)scrollView {
+- (NSScrollView*)scrollView {
   return scrollView_;
 }
 
 - (NSView*)folderView {
   return folderView_;
 }
 
 - (void)setIgnoreAnimations:(BOOL)ignore {
   ignoreAnimations_ = ignore;
 }
 
 - (BookmarkButton*)buttonThatMouseIsIn {
   return buttonThatMouseIsIn_;
 }
 
 @end  // BookmarkBarFolderController