Move ScopedGroupBookmarkActions into bookmarks namespace.

components/bookmarks/browser/bookmark_model.h

Index: components/bookmarks/browser/bookmark_model.h
diff --git a/components/bookmarks/browser/bookmark_model.h b/components/bookmarks/browser/bookmark_model.h
index de7a2c80b1960f86524ceb0a74188b4e4f05e089..c765fa26afac5d976aca05696c7bd5d47fe2f348 100644
--- a/components/bookmarks/browser/bookmark_model.h
+++ b/components/bookmarks/browser/bookmark_model.h
@@ -37,6 +37,10 @@ class FilePath;
 class SequencedTaskRunner;
 }
 
+namespace bookmarks {
+class ScopedGroupBookmarkActions;
+}
+
 namespace favicon_base {
 struct FaviconImageResult;
 }
@@ -282,7 +286,7 @@ class BookmarkModel : public BookmarkService {
   friend class BookmarkCodecTest;
   friend class BookmarkModelTest;
   friend class BookmarkStorage;
-  friend class ScopedGroupBookmarkActions;
+  friend class bookmarks::ScopedGroupBookmarkActions;
   friend class test::TestBookmarkClient;
 
   // Used to order BookmarkNodes by URL.