bookmarks: Move BaseBookmarkModelObserver into 'bookmarks' namespace.

chrome/browser/ui/bookmarks/bookmark_context_menu_controller.h

Index: chrome/browser/ui/bookmarks/bookmark_context_menu_controller.h
diff --git a/chrome/browser/ui/bookmarks/bookmark_context_menu_controller.h b/chrome/browser/ui/bookmarks/bookmark_context_menu_controller.h
index 8f5982296197f7cbe7c7bbd52cd4417733035575..a1e4b38dda4843300d77ab22ba98a8043efc1d2b 100644
--- a/chrome/browser/ui/bookmarks/bookmark_context_menu_controller.h
+++ b/chrome/browser/ui/bookmarks/bookmark_context_menu_controller.h
@@ -40,8 +40,9 @@ class BookmarkContextMenuControllerDelegate {
 
 // BookmarkContextMenuController creates and manages state for the context menu
 // shown for any bookmark item.
-class BookmarkContextMenuController : public BaseBookmarkModelObserver,
-                                      public ui::SimpleMenuModel::Delegate {
+class BookmarkContextMenuController
+    : public bookmarks::BaseBookmarkModelObserver,
+      public ui::SimpleMenuModel::Delegate {
  public:
   // Creates the bookmark context menu.
   // |browser| is used to open the bookmark manager and is NULL in tests.
@@ -85,7 +86,7 @@ class BookmarkContextMenuController : public BaseBookmarkModelObserver,
   // Adds a checkable item to the menu.
   void AddCheckboxItem(int id, int localization_id);
 
-  // Overridden from BaseBookmarkModelObserver:
+  // Overridden from bookmarks::BaseBookmarkModelObserver:
   // Any change to the model results in closing the menu.
   void BookmarkModelChanged() override;