cc : Add DCHECKs to ensure we have valid proprety tree indices at commit

cc/layers/picture_layer_unittest.cc

Index: cc/layers/picture_layer_unittest.cc
diff --git a/cc/layers/picture_layer_unittest.cc b/cc/layers/picture_layer_unittest.cc
index 1ba4387702c4f6f3b52766c88c4ef043901696e5..e7dfd332b45d5aca86d6d846fbd727fe8c3caffb 100644
--- a/cc/layers/picture_layer_unittest.cc
+++ b/cc/layers/picture_layer_unittest.cc
@@ -186,6 +186,7 @@ TEST(PictureLayerTest, ClearVisibleRectWhenNoTiling) {
 
   layer->SavePaintProperties();
   layer->Update();
+  host->BuildPropertyTreesForTesting();
 
   FakeImplTaskRunnerProvider impl_task_runner_provider;
 
@@ -201,7 +202,7 @@ TEST(PictureLayerTest, ClearVisibleRectWhenNoTiling) {
   host_impl.CreatePendingTree();
   host_impl.pending_tree()->SetRootLayerForTesting(
       FakePictureLayerImpl::Create(host_impl.pending_tree(), 1));
-  host_impl.pending_tree()->BuildLayerListForTesting();
+  host_impl.pending_tree()->BuildLayerListAndPropertyTreesForTesting();
 
   FakePictureLayerImpl* layer_impl = static_cast<FakePictureLayerImpl*>(
       host_impl.pending_tree()->root_layer_for_testing());