Terminate EGL when an app goes in the background

This does not happen on high end gfx devices. This happens
only if only one EGL context is initialized in the current
process.

Change-Id: Ibd1737efdf84eef8a84108b05795440d1ae9964e

opengl/libs/EGL/egl_display.h

@@ -91,6 +91,8 @@ public:
     inline bool isValid() const { return magic == '_dpy'; }
     inline bool isAlive() const { return isValid(); }
 
+    inline uint32_t getRefsCount() const { return refs; }
+
     struct strings_t {
         char const * vendor;
         char const * version;