Added persistent logging methods

lib/pixi/deepzoom/tile.js

@@ -198,13 +198,30 @@ export default class Tile extends PIXI.Sprite {
         return null
     }
 
+    /**
+     * Specialized renderWebGL to avoid freezing system
+     *
+     * @param {*} renderer
+     * @memberof Tile
+     */
+    renderWebGL(renderer) {
+        try {
+            super.renderWebGL(renderer)
+        }
+        catch (e) {
+            // We want persistent logging here
+            Logging.error("Error in Tile.renderWebGL: " + e.message)
+        }
+    }
+
     /**
      * Texture received too late. We do not need it.
      * @param {*} url 
      * @param {*} texture 
      */
     static lateTexture(url, texture) {
-        let destroyBase = !registeredTiles.has(url)
+        let destroyBase = Tile.isObsolete(url)
+        console.log("Tile.lateTexture", destroyBase)
         texture.destroy(destroyBase)
     }