Remove old symbols from QOpenGLContext

Task-number: QTBUG-38564
Change-Id: I39a0482e4411cdc644ed34813626c39dacb5b6af
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

src/gui/kernel/qopenglcontext.h

@@ -196,19 +196,13 @@ public:
 
     enum OpenGLModuleType {
         LibGL,
-        LibGLES,
-
-        // ###
-        DesktopGL = LibGL,
-        GLES2 = LibGLES
+        LibGLES
     };
 
     static OpenGLModuleType openGLModuleType();
 
     bool isOpenGLES() const;
 
-    bool isES() const { return isOpenGLES(); } // ###
-
 Q_SIGNALS:
     void aboutToBeDestroyed();