fix(gestures): drag events are debounced

- Performance regressions in menu, sliding item, toggle, go back swipe and scroll up to refresh.
- Buggy sliding item

src/components/item/item-sliding.ts

@@ -315,12 +315,7 @@ export class ItemSliding {
       openAmount = optsWidth + (openAmount - optsWidth) * ELASTIC_FACTOR;
     }
 
-          // this.debouncer.write(() => {
-
-      // });
-    this._dom.write(() => {
     this._setOpenAmount(openAmount, false);
-    });
 
     return openAmount;
   }
@@ -362,7 +357,6 @@ export class ItemSliding {
    * @private
    */
   private calculateOptsWidth() {
-    this._plt.raf(() => {
     if (!this._optsDirty) {
       return;
     }
@@ -378,13 +372,15 @@ export class ItemSliding {
       assert(this._optsWidthLeftSide > 0, '_optsWidthLeftSide should not be zero');
     }
     this._optsDirty = false;
-    });
   }
 
   private _setOpenAmount(openAmount: number, isFinal: boolean) {
     const platform = this._plt;
 
+    if (this._tmr) {
       platform.cancelTimeout(this._tmr);
+      this._tmr = null;
+    }
     this._openAmount = openAmount;
 
     if (isFinal) {

src/gestures/drag-gesture.ts

@@ -110,7 +110,9 @@ export class PanGesture {
   pointerMove(ev: any) {
     assert(this.started === true, 'started must be true');
     if (this.captured) {
+      this.debouncer.write(() => {
         this.onDragMove(ev);
+      });
       return;
     }