cc: Directly use property trees to calculate clip rect

cc/test/layer_tree_settings_for_testing.cc

Index: cc/test/layer_tree_settings_for_testing.cc
diff --git a/cc/test/layer_tree_settings_for_testing.cc b/cc/test/layer_tree_settings_for_testing.cc
new file mode 100644
index 0000000000000000000000000000000000000000..bcd29aee57eda95de2730b5dd63ebd03a792512d
--- /dev/null
+++ b/cc/test/layer_tree_settings_for_testing.cc
@@ -0,0 +1,16 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "cc/test/layer_tree_settings_for_testing.h"
+
+namespace cc {
+
+LayerTreeSettingsForTesting::LayerTreeSettingsForTesting()
+    : LayerTreeSettings() {
+  verify_clip_tree_calculations = true;
+}
+
+LayerTreeSettingsForTesting::~LayerTreeSettingsForTesting() {}
+
+}  // namespace cc