I use Chromium version 48.0.2564.116 Ubuntu 14.04 (64-bit)
When you open a new browser tab, available memory decreases. After the closure of these tabs, the memory is not fully released. This leads to the filling of the free memory and the end of the working day using the swap partition. This is a very rough developers mistake! Firefoh browser Chromium, unlike the more gentle to Linux resources. I hope that the developers Chromium fix this problem.