Merge pull request #5367 from dotansimha/2.0

fix(raf): run requestAnimationFrame w/ correct context

Author: adamdbradley

ionic/util/dom.ts

@@ -5,7 +5,7 @@ let docEle: any = doc.documentElement;
 
 // requestAnimationFrame is polyfilled for old Android
 // within the web-animations polyfill
-export const raf = win.requestAnimationFrame;
+export const raf = win.requestAnimationFrame.bind(win);
 
 export function rafFrames(framesToWait, callback) {
   framesToWait = Math.ceil(framesToWait);