events: Update scroll and touch handlers to not return EventResult.

ash/launcher/launcher_tooltip_manager.cc

Index: ash/launcher/launcher_tooltip_manager.cc
diff --git a/ash/launcher/launcher_tooltip_manager.cc b/ash/launcher/launcher_tooltip_manager.cc
index f99e55204ab7b1b79d43a1410a6900fc2a0c86a4..dfc2a4b511262f199bb70d40f16832133e2f2fc8 100644
--- a/ash/launcher/launcher_tooltip_manager.cc
+++ b/ash/launcher/launcher_tooltip_manager.cc
@@ -278,11 +278,10 @@ ui::EventResult LauncherTooltipManager::OnMouseEvent(ui::MouseEvent* event) {
   return ui::ER_UNHANDLED;
 }
 
-ui::EventResult LauncherTooltipManager::OnTouchEvent(ui::TouchEvent* event) {
+void LauncherTooltipManager::OnTouchEvent(ui::TouchEvent* event) {
   aura::Window* target = static_cast<aura::Window*>(event->target());
   if (widget_ && widget_->IsVisible() && widget_->GetNativeWindow() != target)
     Close();
-  return ui::ER_UNHANDLED;
 }
 
 void LauncherTooltipManager::OnGestureEvent(ui::GestureEvent* event) {