Eliminate ash::Shell access in ShelfView

ash/common/wm_shell.h

 // 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.
 
 #ifndef ASH_COMMON_WM_SHELL_H_
 #define ASH_COMMON_WM_SHELL_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <vector>
 
 #include "ash/ash_export.h"
 #include "ash/common/media_delegate.h"
 #include "ash/common/metrics/user_metrics_action.h"
 #include "ash/common/wm/lock_state_observer.h"
 #include "base/observer_list.h"
+#include "ui/base/ui_base_types.h"
+
+namespace gfx {
+class Point;
+}
 
 namespace views {
 class PointerWatcher;
 }
 
 namespace ash {
 
 class AcceleratorController;
 class AccessibilityDelegate;
 class BrightnessControlDelegate;
@@ skipping 169 matching lines @@
 
   // See aura::client::CursorClient for details on these.
   virtual void LockCursor() = 0;
   virtual void UnlockCursor() = 0;
 
   virtual std::vector<WmWindow*> GetAllRootWindows() = 0;
 
   virtual void RecordUserMetricsAction(UserMetricsAction action) = 0;
   virtual void RecordTaskSwitchMetric(TaskSwitchSource source) = 0;
 
+  // Shows the context menu for the background and the shelf at
+  // |location_in_screen|.
+  virtual void ShowContextMenu(const gfx::Point& location_in_screen,
+                               ui::MenuSourceType source_type) = 0;
+
   // Returns a WindowResizer to handle dragging. |next_window_resizer| is
   // the next WindowResizer in the WindowResizer chain. This may return
   // |next_window_resizer|.
   virtual std::unique_ptr<WindowResizer> CreateDragWindowResizer(
       std::unique_ptr<WindowResizer> next_window_resizer,
       wm::WindowState* window_state) = 0;
 
   virtual std::unique_ptr<WindowCycleEventFilter>
   CreateWindowCycleEventFilter() = 0;
 
@@ skipping 119 matching lines @@
   bool simulate_modal_window_open_for_testing_ = false;
 
 #if defined(OS_CHROMEOS)
   std::unique_ptr<LogoutConfirmationController> logout_confirmation_controller_;
 #endif
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_WM_SHELL_H_