Introduce Property Trees

cc/BUILD.gn

Index: cc/BUILD.gn
diff --git a/cc/BUILD.gn b/cc/BUILD.gn
index d3747a719a39f29fe1d9e76170f97d9287852150..f3084999c0a7462b84a9606760a70668ae586bb1 100644
--- a/cc/BUILD.gn
+++ b/cc/BUILD.gn
@@ -475,6 +475,8 @@ component("cc") {
     "trees/blocking_task_runner.h",
     "trees/damage_tracker.cc",
     "trees/damage_tracker.h",
+    "trees/draw_property_utils.cc",
+    "trees/draw_property_utils.h",
     "trees/layer_sorter.cc",
     "trees/layer_sorter.h",
     "trees/layer_tree_host.cc",
@@ -492,6 +494,10 @@ component("cc") {
     "trees/occlusion.h",
     "trees/occlusion_tracker.cc",
     "trees/occlusion_tracker.h",
+    "trees/property_tree.cc",
+    "trees/property_tree.h",
+    "trees/property_tree_builder.cc",
+    "trees/property_tree_builder.h",
     "trees/proxy.cc",
     "trees/proxy.h",
     "trees/proxy_timing_history.cc",
@@ -813,6 +819,7 @@ test("cc_unittests") {
     "trees/layer_tree_impl_unittest.cc",
     "trees/occlusion_tracker_unittest.cc",
     "trees/occlusion_unittest.cc",
+    "trees/property_tree_unittest.cc",
     "trees/tree_synchronizer_unittest.cc",
 
     # Surfaces test files.