Fix scroll position adjustment for fixed-position layers

cc/trees/draw_property_utils.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/draw_property_utils.h"
 
 #include <vector>
 
 #include "cc/base/math_util.h"
 #include "cc/layers/layer.h"
@@ skipping 59 matching lines @@
 
       content_to_target.Translate(layer->offset_to_transform_parent().x(),
                                   layer->offset_to_transform_parent().y());
       content_to_target.Scale(1.0 / contents_scale_x, 1.0 / contents_scale_y);
 
       gfx::Rect layer_content_rect = gfx::Rect(layer_content_bounds);
       gfx::Rect layer_content_bounds_in_target_space =
           MathUtil::MapEnclosingClippedRect(content_to_target,
                                             layer_content_rect);
       gfx::Rect clip_rect_in_target_space;
-      if (target_node->id > clip_node->id) {
+      if (target_node->id > clip_node->data.transform_id) {
         clip_rect_in_target_space =
             gfx::ToEnclosingRect(MathUtil::ProjectClippedRect(
                 clip_to_target, clip_node->data.combined_clip));
       } else {
         clip_rect_in_target_space =
             gfx::ToEnclosingRect(MathUtil::MapClippedRect(
                 clip_to_target, clip_node->data.combined_clip));
       }
 
       clip_rect_in_target_space.Intersect(layer_content_bounds_in_target_space);
@@ skipping 193 matching lines @@
 
   std::vector<Layer*> layers_to_update;
   const bool subtree_is_visible_from_ancestor = true;
   FindLayersThatNeedVisibleRects(root_layer, *transform_tree,
                                  subtree_is_visible_from_ancestor,
                                  &layers_to_update);
   CalculateVisibleRects(layers_to_update, *clip_tree, *transform_tree);
 }
 
 }  // namespace cc