events: Change gesture-event handler in EventHandler to not return any values.

ash/system/tray/tray_views.cc

Index: ash/system/tray/tray_views.cc
diff --git a/ash/system/tray/tray_views.cc b/ash/system/tray/tray_views.cc
index ca7e625e8276ca52ea33c14ddb868c56b1f72e0e..522ca713a06e57ace3fae011c36edb3feafdb879 100644
--- a/ash/system/tray/tray_views.cc
+++ b/ash/system/tray/tray_views.cc
@@ -182,12 +182,9 @@ void ActionableView::OnPaintFocusBorder(gfx::Canvas* canvas) {
     DrawBorder(canvas, GetLocalBounds());
 }
 
-ui::EventResult ActionableView::OnGestureEvent(ui::GestureEvent* event) {
-  if (event->type() == ui::ET_GESTURE_TAP) {
-    return PerformAction(*event) ? ui::ER_CONSUMED :
-                                  ui::ER_UNHANDLED;
-  }
-  return ui::ER_UNHANDLED;
+void ActionableView::OnGestureEvent(ui::GestureEvent* event) {
+  if (event->type() == ui::ET_GESTURE_TAP && PerformAction(*event))
+    event->SetHandled();
 }
 
 void ActionableView::GetAccessibleState(ui::AccessibleViewState* state) {