Here are the three (yes, 3) processors compared:
The reason why is the i5-3210m is available in two different sockets.
For a processor upgrade, the new processor must be socket, BIOS, and chipset compatible. Only DELL can tell you what processors are supported by THEIR BIOS. So, you must contact DELL for the answer.
Looking at the performance specs, I personally see no reason to upgrade. Your performance increase will be negligible.
If you are doing the upgrade for the graphics, then maybe, but still not significant. But, you will at least be supported on Windows 10.
If you do proceed with the upgrade, and Windows 10 takes the new processor without a reinstall or burp, please report back with the results.
This message was posted on behalf of Intel Corporation
According to your chipset model, these are the compatible processors; Mobile Intel® HM67 Express Chipset Product Specifications, click on "Compatible Products". The processor you are interested in upgrading to is not listed there; however, just like mentioned before the best thing to do is to get in contact with Dell; they should be able to provided a CPU compatible list for your particular model.