bookmarks: Move BaseBookmarkModelObserver into 'bookmarks' namespace.

chrome/browser/android/bookmarks/bookmarks_bridge.h

Index: chrome/browser/android/bookmarks/bookmarks_bridge.h
diff --git a/chrome/browser/android/bookmarks/bookmarks_bridge.h b/chrome/browser/android/bookmarks/bookmarks_bridge.h
index 58edb0aaf503234370bde616dd5368319384de3a..23e80a779ae58ff4b3c32b973d6d806b25ddd7cd 100644
--- a/chrome/browser/android/bookmarks/bookmarks_bridge.h
+++ b/chrome/browser/android/bookmarks/bookmarks_bridge.h
@@ -25,7 +25,7 @@ class Profile;
 // The delegate to fetch bookmarks information for the Android native
 // bookmark page. This fetches the bookmarks, title, urls, folder
 // hierarchy.
-class BookmarksBridge : public BaseBookmarkModelObserver,
+class BookmarksBridge : public bookmarks::BaseBookmarkModelObserver,
                         public PartnerBookmarksShim::Observer {
  public:
   BookmarksBridge(JNIEnv* env, jobject obj, jobject j_profile);
@@ -175,7 +175,7 @@ class BookmarksBridge : public BaseBookmarkModelObserver,
   bool IsFolderAvailable(const BookmarkNode* folder) const;
   void NotifyIfDoneLoading();
 
-  // Override BaseBookmarkModelObserver.
+  // Override bookmarks::BaseBookmarkModelObserver.
   // Called when there are changes to the bookmark model that don't trigger
   // any of the other callback methods. For example, this is called when
   // partner bookmarks change.