Update property trees' bounds delta before updating viewport container sizes.

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 32843bc649493dc95696c0341f55aa2cae745027..92819160c6d5c643b82af935bec906e6e225e573 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -1986,8 +1986,6 @@ void LayerTreeHostImpl::ActivateSyncTree() {
     DCHECK(!recycle_tree_);
     pending_tree_.swap(recycle_tree_);
 
-    UpdateViewportContainerSizes();
-
     // If we commit to the active tree directly, this is already done during
     // commit.
     ActivateAnimations();
@@ -1996,8 +1994,11 @@ void LayerTreeHostImpl::ActivateSyncTree() {
   }
 
   // bounds_delta isn't a pushed property, so the newly-pushed property tree
-  // won't already account for current bounds_delta values.
+  // won't already account for current bounds_delta values. This needs to
+  // happen before calling UpdateViewportContainerSizes().
   active_tree_->UpdatePropertyTreesForBoundsDelta();
+  UpdateViewportContainerSizes();
+
   active_tree_->DidBecomeActive();
   client_->RenewTreePriority();
   // If we have any picture layers, then by activating we also modified tile