Force Quit freezed my Macbook Pro?

Try booting to Recovery

OS X: About OS X Recovery - Apple Support

and repairing the startup disk

Also,

Note the time of the next freeze. After rebooting open the Console app in Finder>Applications>Utilities and look for log entries at the time of the freeze. Post suspicious ones here.

Your problem also occured on my Mac Pro twice yesterday.

Try resetting the SMC

Intel-based Macs: Resetting the System Management Controller (SMC)

What happens if you use a browser other than Chrome?

Try a restart.

Do a backup, using either Time Machine or a cloning program, to ensure files/data can be recovered. Two backups are better than one.

Try setting up another admin user account to see if the same problem continues. If Back-to-My Mac is selected in System Preferences, the Guest account will not work. The intent is to see if it is specific to one account or a system wide problem. This account can be deleted later.

Isolating an issue by using another user account

If the problem is still there, try booting into the Safe Mode using your normal account. Disconnect all peripherals except those needed for the test. Shut down the computer and then power it back up after waiting 10 seconds. Immediately after hearing the startup chime, hold down the shift key and continue to hold it until the gray Apple icon and a progress bar appear. The boot up is significantly slower than normal. This will reset some caches, forces a directory check, and disables all startup and login items, among other things. When you reboot normally, the initial reboot may be slower than normal. If the system operates normally, there may be 3rd party applications which are causing a problem. Try deleting/disabling the third party applications after a restart by using the application un-installer. For each disable/delete, you will need to restart if you don't do them all at once.

Safe Mode

Safe Mode - Mavericks also Yosemite

Do a backup, preferable 2 separate ones on 2 drives. Boot to the Recovery Volume (command - R on a restart or hold down the option/alt key during a restart and select Recovery Volume). Run Disk Utility Verify/Repair and Repair Permissions until you get no errors. Then re-install the OS.

OS X Recovery

OS X Recovery (2)

As Eric Root states: please do a disk backup. Now. Get as much data off this system as you can. Boot from the recovery partition if you can, or from an external USB device containing OS X, or use Target Disk Mode and a cable connected to another local Mac. Get a copy of this data.

From what you are describing, it may be that your system hardware is failing.

As Eric Root indicates, a current backup is far more important than resetting the SMC or any other steps discussed here, as that's the only way that your most current data can (potentially) be recovered. If your disk is failing, then delaying or trying other steps can mean that less data is available, or potentially no data if (when?) the disk fails.

Reinstallation might resolve this, or — if the hardware has failed — you'll be visiting an Apple store or some other preferred repair provider.