Merge "Ensure page scrolls are initialized even for 0 children." into tm-dev am: 1e211e0c03

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/18625747

Change-Id: Ib158460fdc41861dfd50a23c7d38ae0153e04af6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

src/com/android/launcher3/PagedView.java

@@ -727,15 +727,16 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
             pageScrollChanged = true;
         }
 
-        if (childCount == 0) {
-            return;
-        }
-
         if (DEBUG) Log.d(TAG, "PagedView.onLayout()");
 
         pageScrollChanged |= getPageScrolls(pageScrolls, true, SIMPLE_SCROLL_LOGIC);
         mPageScrolls = pageScrolls;
 
+        if (childCount == 0) {
+            onPageScrollsInitialized();
+            return;
+        }
+
         final LayoutTransition transition = getLayoutTransition();
         // If the transition is running defer updating max scroll, as some empty pages could
         // still be present, and a max scroll change could cause sudden jumps in scroll.