Add tests for EGL_EXT_buffer_age

Add basic functionality tests for EGL_EXT_buffer_age. Rendering using
single drawtype as well as combinations of two drawtypes is tested.
Introduce a new FrameSequence class to avoid the situation where edges
of different rectangles are too close to each other.

Change-Id: Id77b50ae962c9580a27d90807bcea4b5f785fadf
5 files changed