Only schedule the icon cache expire when it's needed

src/ol/PluggableMap.js

@@ -54,7 +54,7 @@ import {create as createTransform, apply as applyTransform} from './transform.js
 
 
 /**
- * @typedef {function(PluggableMap, ?FrameState): boolean} PostRenderFunction
+ * @typedef {function(PluggableMap, ?FrameState): any} PostRenderFunction
  */
 
 

src/ol/renderer/Map.js

@@ -280,7 +280,9 @@ class MapRenderer extends Disposable {
    * @protected
    */
   scheduleExpireIconCache(frameState) {
-    frameState.postRenderFunctions.push(/** @type {import("../PluggableMap.js").PostRenderFunction} */ (expireIconCache));
+    if (iconImageCache.canExpireCache()) {
+      frameState.postRenderFunctions.push(expireIconCache);
+    }
   }
 
   /**

src/ol/style/IconImageCache.js

@@ -37,11 +37,18 @@ class IconImageCache {
     this.cacheSize_ = 0;
   }
 
+  /**
+   * @return {boolean} Can expire cache.
+   */
+  canExpireCache() {
+    return this.cacheSize_ > this.maxCacheSize_;
+  }
+
   /**
   * FIXME empty description for jsdoc
   */
   expire() {
-    if (this.cacheSize_ > this.maxCacheSize_) {
+    if (this.canExpireCache()) {
       let i = 0;
       for (const key in this.cache_) {
         const iconImage = this.cache_[key];