We need to share the cb_hande_t between gralloc/EGL/GLES, moved it
into the opengl system common lib.
Also added eglSwapBuffers implementation.
Change-Id: Ia461a48c273af42293aafcf084e457adf03cbed3
This is the emulator opengl implementation of gralloc.
NOTE that it is currently build only if BUILD_EMULATOR_OPENGL_DRIVER
is defined, This is because the other driver peices (EGL/GLES) are
still missing.
Change-Id: If48f5ed619df6efb00cb4e590d99ce49d87875f6