mus: Forward user activity from window server to detector.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index fa1e9a5e8d4a39f03261d44c7153f38db9278a8a..88253d31ba346367776120eecad3cea5afd7d0b4 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -99,9 +99,12 @@
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/system/devicemode.h"
+#include "services/service_manager/public/cpp/connector.h"
+#include "services/ui/public/interfaces/constants.mojom.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/env.h"
 #include "ui/aura/layout_manager.h"
+#include "ui/aura/mus/user_activity_forwarder.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/base/ui_base_switches.h"
@@ -734,6 +737,15 @@ void Shell::Init(const ShellInitParams& init_params) {
 
   wm_shell_->AddShellObserver(lock_state_controller_.get());
 
+  // The connector is unavailable in some tests.
+  if (is_mash && wm_shell_->delegate()->GetShellConnector()) {
+    ui::mojom::UserActivityMonitorPtr user_activity_monitor;
+    wm_shell_->delegate()->GetShellConnector()->BindInterface(
+        ui::mojom::kServiceName, &user_activity_monitor);
+    user_activity_forwarder_ = base::MakeUnique<aura::UserActivityForwarder>(
+        std::move(user_activity_monitor), user_activity_detector_.get());
+  }
+
   drag_drop_controller_.reset(new DragDropController);
   // |screenshot_controller_| needs to be created (and prepended as a
   // pre-target handler) at this point, because |mouse_cursor_filter_| needs to