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

ash/aura/wm_shelf_aura.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/aura/wm_shelf_aura.h"
 
 #include "ash/aura/wm_window_aura.h"
 #include "ash/common/shelf/wm_shelf_observer.h"
 #include "ash/common/wm_window.h"
 #include "ash/shelf/shelf.h"
@@ skipping 115 matching lines @@
 
 void WmShelfAura::UpdateIconPositionForWindow(WmWindow* window) {
   shelf_->UpdateIconPositionForWindow(WmWindowAura::GetAuraWindow(window));
 }
 
 gfx::Rect WmShelfAura::GetScreenBoundsOfItemIconForWindow(WmWindow* window) {
   return shelf_->GetScreenBoundsOfItemIconForWindow(
       WmWindowAura::GetAuraWindow(window));
 }
 
-bool WmShelfAura::ProcessGestureEvent(const ui::GestureEvent& event,
-                                      WmWindow* target_window) {
-  return gesture_handler_.ProcessGestureEvent(
-      event, WmWindowAura::GetAuraWindow(target_window));
+bool WmShelfAura::ProcessGestureEvent(const ui::GestureEvent& event) {
+  // Can be called at login screen.
+  if (!shelf_layout_manager_)
+    return false;
+  return shelf_layout_manager_->ProcessGestureEvent(event);
 }
 
 void WmShelfAura::UpdateAutoHideForMouseEvent(ui::MouseEvent* event) {
   // Auto-hide support for ash_sysui.
   if (Shell::GetInstance()->in_mus() && shelf_layout_manager_)
     shelf_layout_manager_->UpdateAutoHideForMouseEvent(event);
 }
 
 void WmShelfAura::UpdateAutoHideForGestureEvent(ui::GestureEvent* event) {
   // Auto-hide support for ash_sysui.
@@ skipping 42 matching lines @@
 void WmShelfAura::OnAutoHideStateChanged(ShelfAutoHideState new_state) {
   FOR_EACH_OBSERVER(WmShelfObserver, observers_,
                     OnAutoHideStateChanged(new_state));
 }
 
 void WmShelfAura::OnShelfIconPositionsChanged() {
   FOR_EACH_OBSERVER(WmShelfObserver, observers_, OnShelfIconPositionsChanged());
 }
 
 }  // namespace ash