Move BookmarkStorage into bookmarks namespace.

components/bookmarks/browser/bookmark_storage.h

Index: components/bookmarks/browser/bookmark_storage.h
diff --git a/components/bookmarks/browser/bookmark_storage.h b/components/bookmarks/browser/bookmark_storage.h
index ac8a69c77f1a1615c39ff2ac9e720e64ba44c485..a3d5924333c6a118a144d615ab866e0f4ce6ea9f 100644
--- a/components/bookmarks/browser/bookmark_storage.h
+++ b/components/bookmarks/browser/bookmark_storage.h
@@ -18,6 +18,8 @@ namespace base {
 class SequencedTaskRunner;
 }
 
+namespace bookmarks {
+
 // BookmarkLoadDetails is used by BookmarkStorage when loading bookmarks.
 // BookmarkModel creates a BookmarkLoadDetails and passes it (including
 // ownership) to BookmarkStorage. BookmarkStorage loads the bookmarks (and
@@ -163,4 +165,6 @@ class BookmarkStorage : public base::ImportantFileWriter::DataSerializer,
   DISALLOW_COPY_AND_ASSIGN(BookmarkStorage);
 };
 
+}  // namespace bookmarks
+
 #endif  // COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_STORAGE_H_