Revert of TransformTree::SetRootTransformsAndScales should set 'needs_update' on transform tree only

cc/trees/property_tree.cc

Index: cc/trees/property_tree.cc
diff --git a/cc/trees/property_tree.cc b/cc/trees/property_tree.cc
index 3a14b71c034cf2f1da4695dc970fede2316f75af..9faa616a04889f1635f3282f3b3d7c71ade3cc1f 100644
--- a/cc/trees/property_tree.cc
+++ b/cc/trees/property_tree.cc
@@ -738,21 +738,18 @@
   gfx::Transform root_from_screen;
   bool invertible = root_to_screen.GetInverse(&root_from_screen);
   DCHECK(invertible);
-  if (root_to_screen != ToScreen(kRootNodeId)) {
-    TransformNode* root_node = Node(kRootNodeId);
-    root_node->needs_surface_contents_scale = true;
-    root_node->surface_contents_scale = screen_space_scale;
-    SetToScreen(kRootNodeId, root_to_screen);
-    SetFromScreen(kRootNodeId, root_from_screen);
-    set_needs_update(true);
-  }
+  TransformNode* root_node = Node(kRootNodeId);
+  root_node->needs_surface_contents_scale = true;
+  root_node->surface_contents_scale = screen_space_scale;
+  SetToScreen(kRootNodeId, root_to_screen);
+  SetFromScreen(kRootNodeId, root_from_screen);
+  set_needs_update(true);
 
   transform.ConcatTransform(root_from_screen);
   TransformNode* contents_root_node = Node(kContentsRootNodeId);
   if (contents_root_node->post_local != transform) {
     contents_root_node->post_local = transform;
     contents_root_node->needs_local_transform_update = true;
-    set_needs_update(true);
   }
 }