mus: Implement Window Server Capture

components/mus/ws/window_tree_host_impl.cc

Index: components/mus/ws/window_tree_host_impl.cc
diff --git a/components/mus/ws/window_tree_host_impl.cc b/components/mus/ws/window_tree_host_impl.cc
index f1200a6648dfae284c3b77363ad603769772aaf8..59fc52980a1f765bdfcc44b211908adb320481f5 100644
--- a/components/mus/ws/window_tree_host_impl.cc
+++ b/components/mus/ws/window_tree_host_impl.cc
@@ -167,6 +167,18 @@ const mojom::ViewportMetrics& WindowTreeHostImpl::GetViewportMetrics() const {
   return display_manager_->GetViewportMetrics();
 }
 
+void WindowTreeHostImpl::SetCapture(ServerWindow* window,
+                                    bool in_nonclient_area) {
+  ServerWindow* capture_window = event_dispatcher_.capture_window();
+  if (capture_window == window)
+    return;
+  event_dispatcher_.SetCaptureWindow(window, in_nonclient_area);
+  if (window)
+    display_manager_->SetCapture();
+  else
+    display_manager_->ReleaseCapture();
+}
+
 mojom::Rotation WindowTreeHostImpl::GetRotation() const {
   return display_manager_->GetRotation();
 }
@@ -348,8 +360,6 @@ void WindowTreeHostImpl::DispatchInputEventToWindowImpl(ServerWindow* target,
         event_dispatcher_.mouse_cursor_source_window()->cursor());
   }
 
-  // If the event is in the non-client area the event goes to the owner of
-  // the window. Otherwise if the window is an embed root, forward to the
   // embedded window.
   WindowTreeImpl* connection =
       in_nonclient_area
@@ -399,6 +409,10 @@ void WindowTreeHostImpl::OnEvent(const ui::Event& event) {
   event_dispatcher_.ProcessEvent(std::move(mojo_event));
 }
 
+void WindowTreeHostImpl::OnLostCapture() {
+  SetCapture(nullptr, false);
+}
+
 void WindowTreeHostImpl::OnDisplayClosed() {
   if (delegate_)
     delegate_->OnDisplayClosed();
@@ -530,6 +544,11 @@ ServerWindow* WindowTreeHostImpl::GetFocusedWindowForEventDispatcher() {
   return GetFocusedWindow();
 }
 
+void WindowTreeHostImpl::OnLostCapture(ServerWindow* window) {
+  DCHECK(window);
+  connection_manager_->ProcessLostCapture(window);
+}
+
 void WindowTreeHostImpl::DispatchInputEventToWindow(ServerWindow* target,
                                                     bool in_nonclient_area,
                                                     mojom::EventPtr event) {