Revert of Remove UpdateScrollTree

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 <stddef.h>
 
 #include <vector>
 
@@ skipping 725 matching lines @@
     } else if (!can_render_to_separate_surface) {
       node->target_id = EffectTree::kContentsRootNodeId;
     } else if (effect_tree->parent(node)->has_render_surface) {
       node->target_id = node->parent_id;
     } else {
       node->target_id = effect_tree->parent(node)->target_id;
     }
   }
 }
 
+static void UpdateScrollTree(ScrollTree* scroll_tree,
+                             const LayerTreeHost* layer_tree_host) {
+  if (!scroll_tree->needs_update())
+    return;
+
+  for (int i = ScrollTree::kRootNodeId;
+       i < static_cast<int>(scroll_tree->size()); ++i) {
+    ScrollNode* scroll_node = scroll_tree->Node(i);
+    if (Layer* scroll_layer =
+            layer_tree_host->LayerById(scroll_node->owning_layer_id)) {
+      if (Layer* scroll_clip_layer = scroll_layer->scroll_clip_layer()) {
+        scroll_node->scroll_clip_layer_bounds = scroll_clip_layer->bounds();
+      }
+    }
+  }
+}
+
 static void ComputeClips(PropertyTrees* property_trees) {
   DCHECK(!property_trees->transform_tree.needs_update());
   ClipTree* clip_tree = &property_trees->clip_tree;
   if (!clip_tree->needs_update())
     return;
   const int target_effect_id = EffectTree::kContentsRootNodeId;
   const int target_transform_id = TransformTree::kRootNodeId;
   const bool include_expanding_clips = true;
   for (int i = ClipTree::kViewportNodeId;
        i < static_cast<int>(clip_tree->size()); ++i) {
@@ skipping 109 matching lines @@
   DCHECK_EQ(layer_tree_host->property_trees(), property_trees);
   if (property_trees->non_root_surfaces_enabled !=
       can_render_to_separate_surface) {
     property_trees->non_root_surfaces_enabled = can_render_to_separate_surface;
     property_trees->transform_tree.set_needs_update(true);
   }
   if (property_trees->transform_tree.needs_update()) {
     property_trees->clip_tree.set_needs_update(true);
     property_trees->effect_tree.set_needs_update(true);
   }
+  UpdateScrollTree(&property_trees->scroll_tree, layer_tree_host);
   ComputeTransforms(&property_trees->transform_tree);
   ComputeEffects(&property_trees->effect_tree);
   // Computation of clips uses ToScreen which is updated while computing
   // transforms. So, ComputeTransforms should be before ComputeClips.
   ComputeClips(property_trees);
 }
 
 void UpdatePropertyTreesAndRenderSurfaces(LayerImpl* root_layer,
                                           PropertyTrees* property_trees,
                                           bool can_render_to_separate_surface,
@@ skipping 186 matching lines @@
 void UpdateElasticOverscroll(PropertyTrees* property_trees,
                              const Layer* overscroll_elasticity_layer,
                              const gfx::Vector2dF& elastic_overscroll) {
   UpdateElasticOverscrollInternal(property_trees, overscroll_elasticity_layer,
                                   elastic_overscroll);
 }
 
 }  // namespace draw_property_utils
 
 }  // namespace cc