Revert "gpu: Refactor GpuMemoryBuffer framework for multi-process support."

To make merging 4.4.3 easier, will readd later
This reverts commit 6f6db6ed88be93a11c4883bedd2d448f89960e7d.

Change-Id: Ia082c95bdad44a609b74b0fe1ab0a7365e932d6e
Signed-off-by: Josue Rivera <prbassplayer@gmail.com>