WIP: Eliminate event.target() usage from TrayEventFilter

ash/shelf/shelf_tooltip_manager.cc

Index: ash/shelf/shelf_tooltip_manager.cc
diff --git a/ash/shelf/shelf_tooltip_manager.cc b/ash/shelf/shelf_tooltip_manager.cc
index 2aa93fde3d6b1869366ae4969f557c9c1b924ab7..9cd41d6b274616e0a5613f6f017a9b966b02bc2b 100644
--- a/ash/shelf/shelf_tooltip_manager.cc
+++ b/ash/shelf/shelf_tooltip_manager.cc
@@ -174,13 +174,15 @@ void ShelfTooltipManager::ShowTooltipWithDelay(views::View* view) {
 }
 
 void ShelfTooltipManager::OnMousePressed(const ui::MouseEvent& event,
-                                         const gfx::Point& location_in_screen) {
+                                         const gfx::Point& location_in_screen,
+                                         views::Widget* target) {
   // Close on any mouse press events inside or outside the tooltip.
   Close();
 }
 
 void ShelfTooltipManager::OnTouchPressed(const ui::TouchEvent& event,
-                                         const gfx::Point& location_in_screen) {
+                                         const gfx::Point& location_in_screen,
+                                         views::Widget* target) {
   // Close on any touch press events inside or outside the tooltip.
   Close();
 }