cc: Directly use property trees to calculate clip rect

cc/trees/layer_tree_host_impl_unittest.cc

Index: cc/trees/layer_tree_host_impl_unittest.cc
diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index d7c5d19bcfd9e33d5b12d10d0bf00ba11eae1e33..264af100de4932b8c495fbeb8d4f0f65a64cbe2f 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -111,6 +111,7 @@ class LayerTreeHostImplTest : public testing::Test,
     settings.minimum_occlusion_tracking_size = gfx::Size();
     settings.renderer_settings.texture_id_allocation_chunk_size = 1;
     settings.gpu_rasterization_enabled = true;
+    settings.verify_clip_tree_calculations = true;
     return settings;
   }