[cc] Remove unused parameter to DidUpdateScrollOffset

cc/trees/layer_tree_impl.cc

Index: cc/trees/layer_tree_impl.cc
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index 1376cdf6b5ec4b19aebd7f1168b88c25d401f620..d63aa3a3d2468307ce5fb88306df1ca7a8d032a0 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -147,10 +147,11 @@ bool LayerTreeImpl::IsViewportLayerId(int id) const {
 // TODO(sunxd): when we have a layer_id to property_tree index map in property
 // trees, use the transform_id parameter instead of looking for indices from
 // LayerImpls.
-void LayerTreeImpl::DidUpdateScrollOffset(int layer_id, int transform_id) {
+void LayerTreeImpl::DidUpdateScrollOffset(int layer_id) {
   DidUpdateScrollState(layer_id);
   TransformTree& transform_tree = property_trees()->transform_tree;
   ScrollTree& scroll_tree = property_trees()->scroll_tree;
+  int transform_id = -1;
 
   // If pending tree topology changed and we still want to notify the pending
   // tree about scroll offset in the active tree, we may not find the
@@ -175,8 +176,7 @@ void LayerTreeImpl::DidUpdateScrollOffset(int layer_id, int transform_id) {
   }
 
   if (IsActiveTree() && layer_tree_host_impl_->pending_tree())
-    layer_tree_host_impl_->pending_tree()->DidUpdateScrollOffset(layer_id,
-                                                                 transform_id);
+    layer_tree_host_impl_->pending_tree()->DidUpdateScrollOffset(layer_id);
 }
 
 void LayerTreeImpl::DidUpdateScrollState(int layer_id) {