events: Update mouse-event handlers to not return EventResult.

ui/views/corewm/window_modality_controller.cc

Index: ui/views/corewm/window_modality_controller.cc
diff --git a/ui/views/corewm/window_modality_controller.cc b/ui/views/corewm/window_modality_controller.cc
index c6b2a37b7b6d243c3bf1a8cb9497b23d305805c6..58ea579548e7fc4b188417f7e2ff9bb13defacb1 100644
--- a/ui/views/corewm/window_modality_controller.cc
+++ b/ui/views/corewm/window_modality_controller.cc
@@ -109,10 +109,10 @@ void WindowModalityController::OnKeyEvent(ui::KeyEvent* event) {
     event->StopPropagation();
 }
 
-ui::EventResult WindowModalityController::OnMouseEvent(ui::MouseEvent* event) {
+void WindowModalityController::OnMouseEvent(ui::MouseEvent* event) {
   aura::Window* target = static_cast<aura::Window*>(event->target());
-  return ProcessLocatedEvent(target, event) ? ui::ER_CONSUMED :
-                                              ui::ER_UNHANDLED;
+  if (ProcessLocatedEvent(target, event))
+   event->StopPropagation();
 }
 
 void WindowModalityController::OnTouchEvent(ui::TouchEvent* event) {