Added serialization to protobufs for property trees.

cc/trees/property_tree_unittest.cc

Index: cc/trees/property_tree_unittest.cc
diff --git a/cc/trees/property_tree_unittest.cc b/cc/trees/property_tree_unittest.cc
index e72a9ad83a86c7a11be6836addea234bf077b9b3..01bb616ec3806807732c2b7b59ca6baee634ff93 100644
--- a/cc/trees/property_tree_unittest.cc
+++ b/cc/trees/property_tree_unittest.cc
@@ -4,12 +4,29 @@
 
 #include "cc/trees/property_tree.h"
 
+#include "cc/proto/property_tree.pb.h"
 #include "cc/test/geometry_test_utils.h"
 #include "cc/trees/draw_property_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace cc {
 
+TEST(PropertyTreeSerializationTest, EffectNodeDataSerialization) {
+  EffectNodeData original;
+  original.opacity = 0.5f;
+  original.screen_space_opacity = 0.6f;
+  original.has_render_surface = false;
+  original.transform_id = 2;
+  original.clip_id = 3;
+
+  proto::TreeNode proto;
+  original.ToProtobuf(&proto);
+  EffectNodeData result;
+  result.FromProtobuf(proto);
+
+  EXPECT_EQ(original, result);
+}
+
 TEST(PropertyTreeTest, ComputeTransformRoot) {
   TransformTree tree;
   TransformNode& root = *tree.Node(0);