Prevent Chrome to unzip files while downloading
Found: It is an actual bug of Chrome:
See: https://code.google.com/p/chromium/issues/detail?id=47951
and: https://code.google.com/p/chromium/issues/detail?id=268085
Seems this issue didn't get too much credits, and still there is not final solution. I solved in two ways: with an automatic script that compress my mysql file automatically, or using another browser when I can't wait 10 minutes to download a huge uncompresssed dump.