cc: Directly use property trees to calculate clip rect

cc/trees/layer_tree_impl_unittest.cc

Index: cc/trees/layer_tree_impl_unittest.cc
diff --git a/cc/trees/layer_tree_impl_unittest.cc b/cc/trees/layer_tree_impl_unittest.cc
index 195c44b19a511d6bf068212d98359df9cca7ba96..303a7423ab55233ff510575c46c9f403b2a090d0 100644
--- a/cc/trees/layer_tree_impl_unittest.cc
+++ b/cc/trees/layer_tree_impl_unittest.cc
@@ -26,6 +26,7 @@ class LayerTreeImplTest : public LayerTreeHostCommonTest {
   LayerTreeImplTest() : output_surface_(FakeOutputSurface::Create3d()) {
     LayerTreeSettings settings;
     settings.layer_transforms_should_scale_layer_contents = true;
+    settings.verify_clip_tree_calculations = true;
     host_impl_.reset(new FakeLayerTreeHostImpl(settings, &task_runner_provider_,
                                                &shared_bitmap_manager_,
                                                &task_graph_runner_));
@@ -109,6 +110,7 @@ TEST_F(LayerTreeImplTest, UpdateViewportAndHitTest) {
   TestTaskGraphRunner task_graph_runner;
   FakeImplTaskRunnerProvider task_runner_provider;
   LayerTreeSettings settings;
+  settings.verify_clip_tree_calculations = true;
   scoped_ptr<OutputSurface> output_surface = FakeOutputSurface::Create3d();
   scoped_ptr<FakeLayerTreeHostImpl> host_impl;
   host_impl.reset(new FakeLayerTreeHostImpl(settings, &task_runner_provider,