Move BookmarkNodeData into bookmarks namespace.

components/bookmarks/browser/bookmark_node_data_mac.cc

Index: components/bookmarks/browser/bookmark_node_data_mac.cc
diff --git a/components/bookmarks/browser/bookmark_node_data_mac.cc b/components/bookmarks/browser/bookmark_node_data_mac.cc
index 15238855ebc2d5ea5b8f292af0e64161988911f9..2dde55e777fe2c2eb4008ddba76bcb8ff447467c 100644
--- a/components/bookmarks/browser/bookmark_node_data_mac.cc
+++ b/components/bookmarks/browser/bookmark_node_data_mac.cc
@@ -6,6 +6,8 @@
 
 #include "components/bookmarks/browser/bookmark_pasteboard_helper_mac.h"
 
+namespace bookmarks {
+
 // static
 bool BookmarkNodeData::ClipboardContainsBookmarks() {
   return PasteboardContainsBookmarks(ui::CLIPBOARD_TYPE_COPY_PASTE);
@@ -24,3 +26,5 @@ bool BookmarkNodeData::ReadFromClipboard(ui::ClipboardType type) {
 
   return false;
 }
+
+}  // namespace bookmarks