refactored the code so that:
- EGL APIs that can be called before or after eglInitialize() will work by loading the drivers first
- make eglGetDisplay() a lot more efficient
- make sure that EGL drivers are loaded in a thread-safe way
- don't unload the drivers upon calling eglTerminate(), they're now never unloaded, since there is no safe way to do it (some thread could be running)
- updated our EGL version to 1.4
- return better error codes if errors happen during initialization
Merge commit '46e28db8818332e3cda4cc410cc89a1ed7ce4db6'
* commit '46e28db8818332e3cda4cc410cc89a1ed7ce4db6':
fix for [1969185] valgrind errors in new gl stuff
we now look for a config file in /system/lib/egl/egl.cfg that describes the association of a display to a driver.
these drivers are named: /system/lib/egl/lib{[EGL|GLESv1_CM|GLESv2] | GLES}_$TAG.so
ANDROID_swap_rectangle allows to specify the rectangle affected by eglSwapBuffers(), anything outside of this rectangle is unchanged. in particular EGL_BUFFER_DESTROYED only applies to that rectangle. This extension as well as EGL_BUFFER_PRESERVED allow major optimizations on surfaceflinger, which can redraw only the dirty area during compositing.
However, ANDROID_swap_rectangle allows further optimizations in EGL by reducing the amount of copy-back needed. ANDROID_swap_rectangle is particularily important for software implementations.
