There are already functions in CEF that can be used for converting paint buffer to PNG image. See the Image object in API reference. Need to expose two new methods: CreateImage and AddBitmap. This would get rid of PIL dependency and would work on all Pythons without problems. Or a better idea would be to expose new method on the PaintBuffer object: GetImage. Also while at it rename PaintBuffer methods: GetIntPointer --> GetPointer and GetString --> GetBytes.

The PIL image library is only available for Python 2.7. Looks like Python 3 is not supported. This library was abandoned a lot time ago. However there is a new successor called "Pillow": https://pypi.python.org/pypi/Pillow/4.1.0 . It is better to use CEF functions and get rid of PIL dependency.

After this is done update tools/run_examples.py to run screenshot.py as well.