feat(virtual-scroll): apply contain:strict to virtual scroll items

Author: adamdbradley

src/components/virtual-scroll/test/list/app-module.ts

@@ -6,18 +6,17 @@ import { IonicApp, IonicModule } from '../../../..';
   templateUrl: 'main.html'
 })
 export class E2EPage {
-  items: Array<{title: string, date: string}>;
+  items: Array<{title: string}>;
 
   constructor() {
     this.emptyList();
   }
 
   fillList() {
     this.items = [];
-    for (let i = 0; i < 59; i++) {
+    for (let i = 0; i < 500; i++) {
       this.items.push({
-        title: 'Item ' + i,
-        date: '23:' + (59 - i)
+        title: 'Item ' + i
       });
     }
   }

src/components/virtual-scroll/test/list/main.html

@@ -20,16 +20,7 @@
  <ion-list [virtualScroll]="items">
 
   <ion-item text-wrap *virtualItem="let item" (click)="itemTapped($event, item)">
-
-    <ion-row class="item-row">
-      <ion-col class="item-title" width-80>
-        {{item.title}}
-      </ion-col>
-      <ion-col class="item-time" width-20>
-        {{item.date}}
-      </ion-col>
-    </ion-row>
-
+    {{item.title}}
   </ion-item>
 
 </ion-list>

src/components/virtual-scroll/virtual-scroll.scss

@@ -14,6 +14,8 @@
   left: 0;
 
   transition-duration: 0ms;
+
+  contain: strict;
 }
 
 .virtual-scroll .virtual-hidden {