am 70c4f6cf: am 021b7b44: Add a static method to obtain the mime type from extension.

Merge commit '70c4f6cfb4fd48d5153080d038ac0f5b6dbd98ec'

* commit '70c4f6cfb4fd48d5153080d038ac0f5b6dbd98ec':
  Add a static method to obtain the mime type from extension.