mus: Implement Window Server Capture

components/mus/public/cpp/tests/window_tree_client_impl_unittest.cc

Index: components/mus/public/cpp/tests/window_tree_client_impl_unittest.cc
diff --git a/components/mus/public/cpp/tests/window_tree_client_impl_unittest.cc b/components/mus/public/cpp/tests/window_tree_client_impl_unittest.cc
index 669baf9cde3a659bbd5e5ba9a7a782ab8236c59d..e75eb44fc9ce422de4bda4d32f51efdb4b147b2a 100644
--- a/components/mus/public/cpp/tests/window_tree_client_impl_unittest.cc
+++ b/components/mus/public/cpp/tests/window_tree_client_impl_unittest.cc
@@ -663,4 +663,39 @@ TEST_F(WindowTreeClientImplTest, MultipleUnOwnedWindowsDuringDestruction) {
   EXPECT_TRUE(tracker.windows().empty());
 }
 
+// Tests both SetCapture and ReleaseCapture, to ensure that Window is properly
+// updated on failures.
+TEST_F(WindowTreeClientImplTest, ExplicitCapture) {
+  WindowTreeSetup setup;
+  Window* root = setup.GetFirstRoot();
+  ASSERT_TRUE(root);
+
+  root->SetCapture();
+  EXPECT_TRUE(root->has_capture());
+  uint32_t change_id1;
+  ASSERT_TRUE(setup.window_tree()->GetAndClearChangeId(&change_id1));
+  setup.window_tree_client()->OnChangeCompleted(change_id1, false);
+  EXPECT_FALSE(root->has_capture());
+
+  root->SetCapture();
+  EXPECT_TRUE(root->has_capture());
+  uint32_t change_id2;
+  ASSERT_TRUE(setup.window_tree()->GetAndClearChangeId(&change_id2));
+  setup.window_tree_client()->OnChangeCompleted(change_id2, true);
+  EXPECT_TRUE(root->has_capture());
+
+  root->ReleaseCapture();
+  EXPECT_FALSE(root->has_capture());
+  uint32_t change_id3;
+  ASSERT_TRUE(setup.window_tree()->GetAndClearChangeId(&change_id3));
+  setup.window_tree_client()->OnChangeCompleted(change_id3, false);
+  EXPECT_TRUE(root->has_capture());
+
+  root->ReleaseCapture();
+  uint32_t change_id4;
+  ASSERT_TRUE(setup.window_tree()->GetAndClearChangeId(&change_id4));
+  setup.window_tree_client()->OnChangeCompleted(change_id4, true);
+  EXPECT_FALSE(root->has_capture());
+}
+
 }  // namespace mus