Introduce Property Trees

cc/BUILD.gn

Index: cc/BUILD.gn
diff --git a/cc/BUILD.gn b/cc/BUILD.gn
index c744c5b175ad9f6ea7de2c89bec592481d8d4e12..b89a951657b9bc7d9d165c42d37b2465657d74f8 100644
--- a/cc/BUILD.gn
+++ b/cc/BUILD.gn
@@ -472,6 +472,8 @@ 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",
@@ -489,6 +491,10 @@ 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",
@@ -808,6 +814,7 @@ 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.