Change other usages of .size() to .empty() when applicable.

chrome/browser/bookmarks/bookmark_context_menu_controller.cc

 // Copyright (c) 2011 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 "chrome/browser/bookmarks/bookmark_context_menu_controller.h"
 
 #include "base/compiler_specific.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/bookmarks/bookmark_editor.h"
 #include "chrome/browser/bookmarks/bookmark_folder_editor_controller.h"
@@ skipping 251 matching lines @@
     case IDC_BOOKMARK_BAR_REMOVE:
       return !selection_.empty() && !is_root_node;
 
     case IDC_BOOKMARK_BAR_NEW_FOLDER:
     case IDC_BOOKMARK_BAR_ADD_NEW_BOOKMARK:
       return bookmark_utils::GetParentForNewNodes(
           parent_, selection_, NULL) != NULL;
 
     case IDC_COPY:
     case IDC_CUT:
-      return selection_.size() > 0 && !is_root_node;
+      return !selection_.empty() && !is_root_node;
 
     case IDC_PASTE:
       // Paste to selection from the Bookmark Bar, to parent_ everywhere else
       return (!selection_.empty() &&
               bookmark_utils::CanPasteFromClipboard(selection_[0])) ||
              bookmark_utils::CanPasteFromClipboard(parent_);
   }
   return true;
 }
 
 bool BookmarkContextMenuController::GetAcceleratorForCommandId(
     int command_id,
     ui::Accelerator* accelerator) {
   return false;
 }
 
 void BookmarkContextMenuController::BookmarkModelChanged() {
   if (delegate_)
     delegate_->CloseMenu();
 }
 
 bool BookmarkContextMenuController::HasURLs() const {
   for (size_t i = 0; i < selection_.size(); ++i) {
     if (bookmark_utils::NodeHasURLs(selection_[i]))
       return true;
   }
   return false;
 }