I got the conformes test code and execute it with my implementation.
Then, I have found an memory leak.

I check the conformes test codes.
finally, I found out that the conformese test code do not call the eglDestroySurface function.
The conformese test code act as like the followings.
-----------------------------------------------------------------
eglCreateContext
eglCreateWindowSurface
eglMakeCurrent
...
eglDestroyContext
...
eglCreateWindowSurface
eglMakeCurrent
eglMakeCurrent
...
eglDestroyContext
-----------------------------------------------------------------

If eglDestroyContext destory the surface internally, there is the other problem.
-----------------------------------------------------------------
ctx = eglCreateContext
srf = eglCreateWindowSurface
eglMakeCurrent
...
eglDestroyContext( ctx ) //
...
... // srf is removed
...
eglDestroySurface( srf ) // !!! srf is dangling !
-----------------------------------------------------------------

Is there surface leak on the confirmes test code, really ?
If it doesn't, please let me know how do I implement eglDestroyContext ?

thank you.