mus: Implement Window Server Capture

components/mus/view_tree_host_impl.cc

Index: components/mus/view_tree_host_impl.cc
diff --git a/components/mus/view_tree_host_impl.cc b/components/mus/view_tree_host_impl.cc
index 7f04d19d4054242bb6f05d5396e1d8038dc86424..772cbbc3103dba633ac5402d3ed55763625ae656 100644
--- a/components/mus/view_tree_host_impl.cc
+++ b/components/mus/view_tree_host_impl.cc
@@ -31,7 +31,8 @@ ViewTreeHostImpl::ViewTreeHostImpl(
                                               app_impl,
                                               gpu_state,
                                               surfaces_state)),
-      focus_controller_(new FocusController(this)) {
+      focus_controller_(new FocusController(this)),
+      captured_view_(nullptr) {
   display_manager_->Init(this);
   if (client_) {
     client_.set_connection_error_handler(
@@ -68,6 +69,19 @@ const mojo::ViewportMetrics& ViewTreeHostImpl::GetViewportMetrics() const {
   return display_manager_->GetViewportMetrics();
 }
 
+void ViewTreeHostImpl::SetCapture(ServerView* view) {
+  if (captured_view_) {
+    ViewTreeImpl* connection =
+        connection_manager_->GetConnection(captured_view_->id().connection_id);
+    if (connection) {
+      connection->ProcessLostCapture(captured_view_);
+    }
+  }
+  captured_view_ = view;
+  if (captured_view_)
+    display_manager_->SetCapture();
+}
+
 void ViewTreeHostImpl::SetFocusedView(ServerView* new_focused_view) {
   ServerView* old_focused_view = focus_controller_->GetFocusedView();
   if (old_focused_view == new_focused_view)
@@ -154,6 +168,10 @@ void ViewTreeHostImpl::OnEvent(mojo::EventPtr event) {
   event_dispatcher_.OnEvent(event.Pass());
 }
 
+void ViewTreeHostImpl::OnLostCapture() {
+  SetCapture(nullptr);
+}
+
 void ViewTreeHostImpl::OnDisplayClosed() {
   if (delegate_)
     delegate_->OnDisplayClosed();