mash: Remove ash::ShelfGestureHandler and ui::ET_GESTURE_WIN8_EDGE_SWIPE

ash/mus/bridge/wm_shelf_mus.cc

Index: ash/mus/bridge/wm_shelf_mus.cc
diff --git a/ash/mus/bridge/wm_shelf_mus.cc b/ash/mus/bridge/wm_shelf_mus.cc
index 900f66313061a0aa6eca90a88d879d9ec21be9fc..39e10de2d0cb8b2ec44291c154db4dc9a728b596 100644
--- a/ash/mus/bridge/wm_shelf_mus.cc
+++ b/ash/mus/bridge/wm_shelf_mus.cc
@@ -111,8 +111,7 @@ gfx::Rect WmShelfMus::GetScreenBoundsOfItemIconForWindow(WmWindow* window) {
   return gfx::Rect();
 }
 
-bool WmShelfMus::ProcessGestureEvent(const ui::GestureEvent& event,
-                                     WmWindow* target_window) {
+bool WmShelfMus::ProcessGestureEvent(const ui::GestureEvent& event) {
   NOTIMPLEMENTED();
   return false;
 }