fixup! fix(material-experimental/mdc-slider): sync ui on mouseenter

Author: wagnermaciel

src/material-experimental/mdc-slider/slider.ts

@@ -680,9 +680,7 @@ export class MatSlider extends _MatSliderMixinBase
       this._foundation.destroy();
     }
     this._dirChangeSubscription.unsubscribe();
-
-    const evtType = this._getEventTypeTypeForUISyncEventListener();
-    this._elementRef.nativeElement.removeEventListener(evtType, this._layout);
+    this._removeUISyncEventListener();
   }
 
   /** Returns true if the language direction for this slider element is right to left. */
@@ -703,19 +701,16 @@ export class MatSlider extends _MatSliderMixinBase
     // "mousedown" as the default for when a browser does not support pointer events. While we
     // would prefer to use "mousedown" as the default, for some reason it does not work (the
     // callback is never triggered).
-    const evtType = this._getEventTypeTypeForUISyncEventListener();
+    const evtType = this._SUPPORTS_POINTER_EVENTS ? 'pointerdown' : 'mouseenter';
     this._elementRef.nativeElement.addEventListener(evtType, this._layout);
+    this._elementRef.nativeElement.addEventListener('touchstart', this._layout);
   }
 
-  /** Returns the event type that should be used for syncing the slider UI with the foundation. */
-  private _getEventTypeTypeForUISyncEventListener(): string {
-    if (this._SUPPORTS_POINTER_EVENTS) {
-      return 'pointerdown';
-    }
-    if (this._platform.isBrowser) {
-      return 'mousedown';
-    }
-    return 'touchstart';
+  /** Removes the event listener that keeps sync the slider UI and the foundation in sync. */
+  _removeUISyncEventListener(): void {
+    const evtType = this._SUPPORTS_POINTER_EVENTS ? 'pointerdown' : 'mouseenter';
+    this._elementRef.nativeElement.removeEventListener(evtType, this._layout);
+    this._elementRef.nativeElement.removeEventListener('touchstart', this._layout);
   }
 
   /** Wrapper function for calling layout (needed for adding & removing an event listener). */