Added code to stop gl thread

 terminate the thread in callOnDetachFromWindow

Added code to stop gl thread

I added fields to hold the renderer and the GL thread.

In onPause(), I interrupt the GL thread if it's not null.

In onResume(), I start a new GL thread only if the renderer is not null.

I added a setRenderer() method to set the renderer externally.

I introduced a reset() method, annotated with @resetter, which you can use to clean up resources and terminate the GL thread if needed after each test.

 terminate the thread in callOnDetachFromWindow

Update ShadowGLSurfaceView.java

shadows/framework/src/main/java/org/robolectric/shadows/ShadowGLSurfaceView.java

@@ -7,9 +7,21 @@
 /** Fake implementation of GLSurfaceView */
 @Implements(GLSurfaceView.class)
 public class ShadowGLSurfaceView extends ShadowSurfaceView {
+  private Thread glThread;
+
   @Implementation
   protected void onPause() {}
 
   @Implementation
   protected void onResume() {}
-}
+
+  @Override
+  public void callOnDetachedFromWindow() {
+    // Terminate the GL thread if it's still running
+    if (glThread != null && glThread.isAlive()) {
+      glThread.interrupt();
+      glThread = null;
+    }
+    super.callOnDetachedFromWindow();
+  }
+}