mus: Introduce API for embedder to dispatch event to the embeded client.

components/mus/public/cpp/lib/window_tree_client.cc

Index: components/mus/public/cpp/lib/window_tree_client.cc
diff --git a/components/mus/public/cpp/lib/window_tree_client.cc b/components/mus/public/cpp/lib/window_tree_client.cc
index 7a43101ff6a809ad755b710c8bb4739fd90096c1..362595876fcf31d1089f7e8ba1a071655923e8b4 100644
--- a/components/mus/public/cpp/lib/window_tree_client.cc
+++ b/components/mus/public/cpp/lib/window_tree_client.cc
@@ -30,6 +30,8 @@
 
 namespace mus {
 
+namespace {
+
 void DeleteWindowTreeClient(WindowTreeClient* client) { delete client; }
 
 Id MakeTransportId(ClientSpecificId client_id, ClientSpecificId local_id) {
@@ -61,6 +63,8 @@ Window* AddWindowToClient(WindowTreeClient* client,
   return window;
 }
 
+}  // namespace
+
 Window* BuildWindowTree(WindowTreeClient* client,
                         const mojo::Array<mojom::WindowDataPtr>& windows,
                         Window* initial_parent) {
@@ -100,6 +104,7 @@ WindowTreeClient::WindowTreeClient(
       tree_(nullptr),
       delete_on_no_roots_(!window_manager_delegate),
       in_destructor_(false),
+      event_handler_binding_(this),
       weak_factory_(this) {
   // Allow for a null request in tests.
   if (request.is_pending())
@@ -1003,6 +1008,17 @@ void WindowTreeClient::OnWindowPredefinedCursorChanged(
   WindowPrivate(window).LocalSetPredefinedCursor(cursor);
 }
 
+void X() {
+  LOG(ERROR) << "FFFFFFFFFFFFFFFFUCK";
+}
+
+void WindowTreeClient::RequestInputEventHandler(
+    mojom::InputEventHandlerRequest request) {
+  LOG(ERROR) << "Yes";
+  event_handler_binding_.Bind(std::move(request));
+  event_handler_binding_.set_connection_error_handler(base::Bind(&X));
+}
+
 void WindowTreeClient::OnChangeCompleted(uint32_t change_id, bool success) {
   std::unique_ptr<InFlightChange> change(std::move(in_flight_map_[change_id]));
   in_flight_map_.erase(change_id);
@@ -1178,4 +1194,18 @@ void WindowTreeClient::SetUnderlaySurfaceOffsetAndExtendedHitArea(
   }
 }
 
+void WindowTreeClient::OnInputEvent(uint32_t window_id,
+                                    std::unique_ptr<ui::Event> event,
+                                    const OnInputEventCallback& callback) {
+  Window* window = GetWindowByServerId(window_id);  // May be null.
+  LOG(ERROR) << "X: " << event->name() << " " << window << " " << window_id
+      << " " << windows_.size();
+  if (!window && !windows_.empty())
+    window = windows_.begin()->second;
+  if (window && window->input_event_handler_) {
+    window->input_event_handler_->OnWindowInputEvent(window, *event, nullptr);
+  }
+  callback.Run(true);
+}
+
 }  // namespace mus