mus: Implement Window Server Capture

components/mus/ws/window_tree_impl.cc

Index: components/mus/ws/window_tree_impl.cc
diff --git a/components/mus/ws/window_tree_impl.cc b/components/mus/ws/window_tree_impl.cc
index d783982079ea319788602ebe4645527d9963ad93..d778a026d7bf63c8a60624e4aea76ba14b57c0c6 100644
--- a/components/mus/ws/window_tree_impl.cc
+++ b/components/mus/ws/window_tree_impl.cc
@@ -403,6 +403,11 @@ bool WindowTreeImpl::ShouldRouteToWindowManager(
   return true;
 }
 
+void WindowTreeImpl::ProcessLostCapture(
+    const ServerWindow* old_capture_window) {
+  client()->OnLostCapture(WindowIdToTransportId(old_capture_window->id()));
+}
+
 bool WindowTreeImpl::IsWindowKnown(const ServerWindow* window) const {
   return known_windows_.count(WindowIdToTransportId(window->id())) > 0;
 }
@@ -697,6 +702,30 @@ void WindowTreeImpl::GetWindowTree(
   callback.Run(WindowsToWindowDatas(windows));
 }
 
+void WindowTreeImpl::SetCapture(uint32_t change_id, Id window_id) {
+  ServerWindow* window = GetWindow(WindowIdFromTransportId(window_id));
+  WindowTreeHostImpl* host = GetHost();
+  bool success = window && access_policy_->CanSetCapture(window) && host &&
+                 access_policy_->CanSetCapture(host->GetCaptureWindow());
+  if (success) {
+    Operation op(this, connection_manager_, OperationType::SET_CAPTURE);
+    host->SetCapture(window);
+  }
+  client_->OnChangeCompleted(change_id, success);
+}
+
+void WindowTreeImpl::ReleaseCapture(uint32_t change_id, Id window_id) {
+  ServerWindow* window = GetWindow(WindowIdFromTransportId(window_id));
+  WindowTreeHostImpl* host = GetHost();
+  bool success =
+      window && host && access_policy_->CanSetCapture(host->GetCaptureWindow());
+  if (success) {
+    Operation op(this, connection_manager_, OperationType::RELEASE_CAPTURE);
+    host->SetCapture(nullptr);
+  }
+  client_->OnChangeCompleted(change_id, success);
+}
+
 void WindowTreeImpl::SetWindowBounds(uint32_t change_id,
                                      Id window_id,
                                      mojo::RectPtr bounds) {