🐛 Fix scrollTo with layers (#17563)

* Fix scrollTo with layers * Add Math.max
ampproject · Aug 24, 2018 · a2f9c1d · a2f9c1d
1 parent 70eb785
commit a2f9c1d
Showing 1 changed file with 8 additions and 12 deletions.
diff --git a/src/service/viewport/viewport-impl.js b/src/service/viewport/viewport-impl.js
@@ -555,19 +555,15 @@ export class Viewport {
         offset = 0;
         break;
     }
-    let newScrollTop;
-    let curScrollTopPromise;
 
-    if (this.useLayers_) {
-      newScrollTop = elementRect.top + offset;
-      curScrollTopPromise = Promise.resolve(0);
-    } else {
-      const calculatedScrollTop = elementRect.top - this.paddingTop_ + offset;
-      newScrollTop = Math.max(0, calculatedScrollTop);
-      curScrollTopPromise = this.getElementScrollTop_(parent);
-    }
-
-    return curScrollTopPromise.then(curScrollTop => {
+    return this.getElementScrollTop_(parent).then(curScrollTop => {
+      let newScrollTop;
+      if (this.useLayers_) {
+        newScrollTop = Math.max(0, elementRect.top + offset + curScrollTop);
+      } else {
+        const calculatedScrollTop = elementRect.top - this.paddingTop_ + offset;
+        newScrollTop = Math.max(0, calculatedScrollTop);
+      }
       if (newScrollTop == curScrollTop) {
         return;
       }