Android SurfaceViewRenderer: Only clear image in release() if initialized

talk/app/webrtc/java/android/org/webrtc/SurfaceViewRenderer.java

 /*
  * libjingle
  * Copyright 2015 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 188 matching lines @@
       // when the EGL context is lost. It might be dangerous to delete them manually in
       // Activity.onDestroy().
       renderThreadHandler.postAtFrontOfQueue(new Runnable() {
         @Override public void run() {
           drawer.release();
           drawer = null;
           if (yuvTextures != null) {
             GLES20.glDeleteTextures(3, yuvTextures, 0);
             yuvTextures = null;
           }
-          // Clear last rendered image to black.
-          GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
-          eglBase.swapBuffers();
+          if (eglBase.hasSurface()) {
+            // Clear last rendered image to black.
+            GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
+            eglBase.swapBuffers();
+          }
           eglBase.release();
           eglBase = null;
         }
       });
       // Don't accept any more frames or messages to the render thread.
       renderThreadHandler = null;
     }
     // Quit safely to make sure the EGL/GL cleanup posted above is executed.
     renderThread.quitSafely();
     synchronized (frameLock) {
@@ skipping 287 matching lines @@
       if (framesReceived > 0 && framesRendered > 0) {
         final long timeSinceFirstFrameNs = System.nanoTime() - firstFrameTimeNs;
         Logging.d(TAG, "Duration: " + (int) (timeSinceFirstFrameNs / 1e6) +
             " ms. FPS: " + (float) framesRendered * 1e9 / timeSinceFirstFrameNs);
         Logging.d(TAG, "Average render time: "
             + (int) (renderTimeNs / (1000 * framesRendered)) + " us.");
       }
     }
   }
 }