What is EGL and GL mtrack in Android Memory Dump

GL mtrack is driver-reported GL memory usage. It's primarily the sum of GL texture sizes, GL command buffers, fixed global driver RAM overheads, etc.

EGL mtrack is gralloc memory usage. It's primarily the sum of the SurfaceView/TextureView.

EGL and GL shows here memory consumed by Graphics layer basically. I am sure you are running adb shell dumpsys meminfo command on Android lollipop device. Actually dumpsys meminfo tool/command has been modified in lollipop to calculate and display graphics memory.

In old version (KitKat or older) you can not find EGL and GL information although graphics consumed memory in KitKat or older versions also.

This is we can request Google to update their documentation to explain new memory components also. In short you can say it is bug in documentation of Android. They should update it as per latest implementation of adb shell dumpsys meminfo tool/command.

References:

EGL - http://en.wikipedia.org/wiki/EGL_(API)

GL - http://en.wikipedia.org/wiki/OpenGL