I've seen that icon appear as well and, so far, have steered well clear.
Not sure about using system restore as only certain file (paths / types) are in the scope of system restore.
Chrome's bookmarks are stored in a file called Bookmarks typically located at:
If I were you I would search your entire drive for any and all files called Bookmarks. The main bookmarks file does not have an extension, but Chrome also makes a backup called Bookmarks.bak
Before doing anything else, I would then make a copy (e.g. to a USB drive) of all such Bookmarks files.
Once you've got a copy of the files, open each one up using Notepad and look at the contents (they are only text files so will open readily with Notepad).
There's a lot of "surrounding" information in the Bookmarks file, but at that stage you should, at least, be able to see if any of the files have your bookmarks embedded in them. If you find the right one, make sure you keep a secure copy of it.
That's step 1. If that yields results, I'll get back on step 2.