Implement hit tests/client area.

ui/aura/mus/window_tree_host_mus_unittest.cc

+// 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 "ui/aura/mus/window_tree_host_mus.h"
+
+#include "ui/aura/test/aura_mus_test_base.h"
+#include "ui/aura/test/mus/test_window_tree.h"
+
+namespace aura {
+
+using WindowTreeHostMusTest = aura::test::AuraMusClientTestBase;
+
+TEST_F(WindowTreeHostMusTest, UpdateClientArea) {
+  std::unique_ptr<WindowTreeHostMus> window_tree_host_mus =
+      base::MakeUnique<WindowTreeHostMus>(window_tree_client_impl());
+
+  gfx::Insets new_insets(10, 11, 12, 13);
+  window_tree_host_mus->SetClientArea(new_insets);
+  EXPECT_EQ(new_insets, window_tree()->last_client_area());
+}
+
+TEST_F(WindowTreeHostMusTest, SetHitTestMask) {
+  std::unique_ptr<WindowTreeHostMus> window_tree_host_mus =
+      base::MakeUnique<WindowTreeHostMus>(window_tree_client_impl());
+
+  EXPECT_FALSE(window_tree()->last_hit_test_mask().has_value());
+  gfx::Rect mask(10, 10, 10, 10);
+  window_tree_host_mus->SetHitTestMask(mask);
+  ASSERT_TRUE(window_tree()->last_hit_test_mask().has_value());
+  EXPECT_EQ(mask, window_tree()->last_hit_test_mask());
+
+  window_tree_host_mus->SetHitTestMask(base::nullopt);
+  ASSERT_FALSE(window_tree()->last_hit_test_mask().has_value());
+}
+
+}  // namespace aura