mash: Preliminary support for widget hit test masks

components/mus/ws/event_dispatcher_unittest.cc

Index: components/mus/ws/event_dispatcher_unittest.cc
diff --git a/components/mus/ws/event_dispatcher_unittest.cc b/components/mus/ws/event_dispatcher_unittest.cc
index 07ffa0f39d67161710f735a75baccb7af8fa4f1b..424d07c7b450b81b5a3034173997acdc532c43cb 100644
--- a/components/mus/ws/event_dispatcher_unittest.cc
+++ b/components/mus/ws/event_dispatcher_unittest.cc
@@ -654,6 +654,26 @@ TEST_F(EventDispatcherTest, AdditionalClientArea) {
   EXPECT_FALSE(details->in_nonclient_area);
 }
 
+TEST_F(EventDispatcherTest, HitTestMask) {
+  std::unique_ptr<ServerWindow> child = CreateChildWindow(WindowId(1, 3));
+
+  root_window()->SetBounds(gfx::Rect(0, 0, 100, 100));
+  child->SetBounds(gfx::Rect(10, 10, 20, 20));
+  child->set_hit_test_mask(gfx::Rect(2, 2, 16, 16));
+
+  // Press in the masked out area.
+  const ui::PointerEvent press_event(ui::MouseEvent(
+      ui::ET_MOUSE_PRESSED, gfx::Point(11, 11), gfx::Point(11, 11),
+      base::TimeDelta(), ui::EF_LEFT_MOUSE_BUTTON, ui::EF_LEFT_MOUSE_BUTTON));
+  event_dispatcher()->ProcessEvent(press_event);
+
+  // Event went through the child window and hit the root.
+  std::unique_ptr<DispatchedEventDetails> details =
+      test_event_dispatcher_delegate()->GetAndAdvanceDispatchedEventDetails();
+  EXPECT_EQ(root_window(), details->window);
+  EXPECT_FALSE(details->in_nonclient_area);
+}
+
 TEST_F(EventDispatcherTest, DontFocusOnSecondDown) {
   std::unique_ptr<ServerWindow> child1 = CreateChildWindow(WindowId(1, 3));
   std::unique_ptr<ServerWindow> child2 = CreateChildWindow(WindowId(1, 4));