Querying for this problem on Google finds several millions of articles and posts
about the problem of missing passwords in Chrome.
Narrowing the Google search to the Chromium bug-list website of
code.google.com finds "only" 11,000 results (!!).
Here are the latest three issues :
Issue 268361: All my stored passwords are lost (Aug 5, 2013)
Issue 351343: saved passwords disappeared (Mar 11, 2014)
Issue 468275: Saved passwords missing in chrome (Mar 18, 2015)
This is not one bug that appears and reappears, but very many bugs,
each one alone capable of destroying the stored passwords.
As such, I believe that letting Chrome manage your passwords is rather
like playing Russian roulette.
You would be much better off using a third-party password manager.
Using a specialized product is much safer, with the added benefits
that your passwords are available across multiple computers and devices,
as well as multiple browsers, so you are not captive of just one browser.
The best one I have found is LastPass, where
the passwords and the contents of all the fields in their containing forms are
encrypted and saved on their servers.
The encryption is done on your side and using your master password for protection, so the LastPass website has no idea of what is stored on their servers.
The power of this concept was proven lately when the LastPass website was hacked. The results were rather minor for the users, as the most that the hackers managed to get were the password hints, since the encrypted passwords themselves were useless to them.
For more info about how LastPass was designed to stand off such attacks, see the article :
LastPass Is Breached: Do You Need To Change Your Master Password?