Record root layer's position in its TransformNode

cc/trees/property_tree_builder.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/property_tree_builder.h"
 
 #include <map>
 #include <set>
 
 #include "cc/base/math_util.h"
@@ skipping 264 matching lines @@
     node->data.needs_sublayer_scale = true;
     node->data.layer_scale_factor = data_from_ancestor.device_scale_factor;
     if (data_from_ancestor.in_subtree_of_page_scale_layer)
       node->data.layer_scale_factor *= data_from_ancestor.page_scale_factor;
   }
 
   node->data.source_node_id = source_index;
   if (is_root) {
     node->data.post_local.Scale(post_local_scale_factor,
                                 post_local_scale_factor);
+    node->data.post_local.Translate(layer->position().x(),
+                                    layer->position().y());
   } else {
     node->data.post_local_scale_factor = post_local_scale_factor;
     node->data.source_offset = source_offset;
     node->data.update_post_local_transform(layer->position(),
                                            layer->transform_origin());
   }
 
   if (!layer->scroll_parent())
     node->data.scroll_offset = layer->CurrentScrollOffset();
 
@@ skipping 158 matching lines @@
     float device_scale_factor,
     const gfx::Rect& viewport,
     const gfx::Transform& device_transform,
     PropertyTrees* property_trees) {
   BuildPropertyTreesTopLevelInternal(
       root_layer, page_scale_layer, page_scale_factor, device_scale_factor,
       viewport, device_transform, property_trees);
 }
 
 }  // namespace cc