EGL: check that display is still valid
am: d6e9946cdd

Change-Id: I6d5f5e6f4790f16c1bd52f96743c7e138973a1b4
diff --git a/opengl/libs/EGL/egl_display.cpp b/opengl/libs/EGL/egl_display.cpp
index e335a6c..1e39aae 100644
--- a/opengl/libs/EGL/egl_display.cpp
+++ b/opengl/libs/EGL/egl_display.cpp
@@ -66,7 +66,10 @@
 
 egl_display_t* egl_display_t::get(EGLDisplay dpy) {
     uintptr_t index = uintptr_t(dpy)-1U;
-    return (index >= NUM_DISPLAYS) ? NULL : &sDisplay[index];
+    if (index >= NUM_DISPLAYS || !sDisplay[index].isValid()) {
+        return nullptr;
+    }
+    return &sDisplay[index];
 }
 
 void egl_display_t::addObject(egl_object_t* object) {