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

cc/proto/property_tree.proto

Index: cc/proto/property_tree.proto
diff --git a/cc/proto/property_tree.proto b/cc/proto/property_tree.proto
index 50cfb45c95ac576969c5ebbe70fc439b0cc01eeb..bf661dbe66b2a55145b3c733ccf13307069c5991 100644
--- a/cc/proto/property_tree.proto
+++ b/cc/proto/property_tree.proto
@@ -42,22 +42,23 @@ message TranformNodeData {
   optional bool node_and_ancestors_have_only_integer_translation = 21;
   optional bool scrolls = 22;
   optional bool needs_sublayer_scale = 23;
-  optional bool affected_by_inner_viewport_bounds_delta_x = 24;
-  optional bool affected_by_inner_viewport_bounds_delta_y = 25;
-  optional bool affected_by_outer_viewport_bounds_delta_x = 26;
-  optional bool affected_by_outer_viewport_bounds_delta_y = 27;
-  optional bool in_subtree_of_page_scale_layer = 28;
-  optional float post_local_scale_factor = 29;
-  optional float local_maximum_animation_target_scale = 30;
-  optional float local_starting_animation_scale = 31;
-  optional float combined_maximum_animation_target_scale = 32;
-  optional float combined_starting_animation_scale = 33;
-
-  optional Vector2dF sublayer_scale = 34;
-  optional ScrollOffset scroll_offset = 35;
-  optional Vector2dF scroll_snap = 36;
-  optional Vector2dF source_offset = 37;
-  optional Vector2dF source_to_parent = 38;
+  optional bool is_3d_sorted = 24;
+  optional bool affected_by_inner_viewport_bounds_delta_x = 25;
+  optional bool affected_by_inner_viewport_bounds_delta_y = 26;
+  optional bool affected_by_outer_viewport_bounds_delta_x = 27;
+  optional bool affected_by_outer_viewport_bounds_delta_y = 28;
+  optional bool in_subtree_of_page_scale_layer = 29;
+  optional float post_local_scale_factor = 30;
+  optional float local_maximum_animation_target_scale = 31;
+  optional float local_starting_animation_scale = 32;
+  optional float combined_maximum_animation_target_scale = 33;
+  optional float combined_starting_animation_scale = 34;
+
+  optional Vector2dF sublayer_scale = 35;
+  optional ScrollOffset scroll_offset = 36;
+  optional Vector2dF scroll_snap = 37;
+  optional Vector2dF source_offset = 38;
+  optional Vector2dF source_to_parent = 39;
 }
 
 // Proto for struct ClipNodeData.