cc:: Add transform nodes at boundaries of 3d rendering contexts

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 <stddef.h>
 
 #include <map>
 #include <set>
@@ skipping 214 matching lines @@
   const bool has_surface = created_render_surface;
 
   // A transform node is needed to change the render target for subtree when
   // a scroll child's render target is different from the scroll parent's render
   // target.
   const bool scroll_child_has_different_target =
       layer->scroll_parent() &&
       layer->parent()->effect_tree_index() !=
           layer->scroll_parent()->effect_tree_index();
 
+  const bool is_at_boundary_of_3d_rendering_context =
+      layer->parent()
+          ? layer->parent()->sorting_context_id() != layer->sorting_context_id()
+          : layer->Is3dSorted();
   bool requires_node = is_root || is_scrollable || has_significant_transform ||
                        has_any_transform_animation || has_surface || is_fixed ||
                        is_page_scale_layer || is_overscroll_elasticity_layer ||
-                       scroll_child_has_different_target;
+                       scroll_child_has_different_target ||
+                       is_at_boundary_of_3d_rendering_context;
 
   LayerType* transform_parent = GetTransformParent(data_from_ancestor, layer);
   DCHECK(is_root || transform_parent);
 
   int parent_index = kRootPropertyTreeNodeId;
   if (transform_parent)
     parent_index = transform_parent->transform_tree_index();
 
   int source_index = parent_index;
 
@@ skipping 56 matching lines @@
   data_for_children->transform_tree->Insert(TransformNode(), parent_index);
 
   TransformNode* node = data_for_children->transform_tree->back();
   layer->SetTransformTreeIndex(node->id);
   if (layer->mask_layer())
     layer->mask_layer()->SetTransformTreeIndex(node->id);
 
   node->data.scrolls = is_scrollable;
   node->data.flattens_inherited_transform = data_for_children->should_flatten;
 
+  node->data.sorting_context_id = layer->sorting_context_id();
+
   if (layer == data_from_ancestor.page_scale_layer)
     data_for_children->in_subtree_of_page_scale_layer = true;
   node->data.in_subtree_of_page_scale_layer =
       data_for_children->in_subtree_of_page_scale_layer;
 
   // Surfaces inherently flatten transforms.
   data_for_children->should_flatten =
       layer->should_flatten_transform() || has_surface;
   DCHECK_GT(data_from_ancestor.effect_tree->size(), 0u);
 
@@ skipping 480 matching lines @@
     const gfx::Transform& device_transform,
     PropertyTrees* property_trees) {
   BuildPropertyTreesTopLevelInternal(
       root_layer, page_scale_layer, inner_viewport_scroll_layer,
       outer_viewport_scroll_layer, overscroll_elasticity_layer,
       elastic_overscroll, page_scale_factor, device_scale_factor, viewport,
       device_transform, property_trees);
 }
 
 }  // namespace cc