Google is now discontinuing Chrome’s Bookmark manager because of its now popularity and bad user interface. When Google launched it complaints started quickly flowing in on the Google Product Forums that it was confusing and hard to use.
With search, images and other fancy additions, it probably seemed like a good idea at the time. But the changes weren’t very useful, and made bookmarking cluttered and slow on a browser most people go to for speed. If you still want it, Google said you can download it as an extension.