Use OnceCallback on Mojo interfaces in //ash

ash/shelf/shelf_view_unittest.cc

 // Copyright (c) 2012 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/shelf/shelf_view.h"
 
 #include <algorithm>
 #include <memory>
 #include <utility>
 #include <vector>
@@ skipping 134 matching lines @@
 
   size_t item_selected_count() const { return item_selected_count_; }
   void set_item_selected_action(ShelfAction item_selected_action) {
     item_selected_action_ = item_selected_action;
   }
 
   // ShelfItemDelegate:
   void ItemSelected(std::unique_ptr<ui::Event> event,
                     int64_t display_id,
                     ShelfLaunchSource source,
-                    const ItemSelectedCallback& callback) override {
+                    ItemSelectedCallback callback) override {
     item_selected_count_++;
-    callback.Run(item_selected_action_, base::nullopt);
+    std::move(callback).Run(item_selected_action_, base::nullopt);
   }
   void ExecuteCommand(uint32_t command_id, int32_t event_flags) override {}
   void Close() override {}
 
  private:
   size_t item_selected_count_ = 0;
   ShelfAction item_selected_action_ = SHELF_ACTION_NONE;
 
   DISALLOW_COPY_AND_ASSIGN(ShelfItemSelectionTracker);
 };
@@ skipping 1832 matching lines @@
 class ListMenuShelfItemDelegate : public ShelfItemDelegate {
  public:
   ListMenuShelfItemDelegate() : ShelfItemDelegate(ShelfID()) {}
   ~ListMenuShelfItemDelegate() override {}
 
  private:
   // ShelfItemDelegate:
   void ItemSelected(std::unique_ptr<ui::Event> event,
                     int64_t display_id,
                     ShelfLaunchSource source,
-                    const ItemSelectedCallback& callback) override {
+                    ItemSelectedCallback callback) override {
     // Two items are needed to show a menu; the data in the items is not tested.
     std::vector<mojom::MenuItemPtr> items;
     items.push_back(mojom::MenuItem::New());
     items.push_back(mojom::MenuItem::New());
-    callback.Run(SHELF_ACTION_NONE, std::move(items));
+    std::move(callback).Run(SHELF_ACTION_NONE, std::move(items));
   }
   void ExecuteCommand(uint32_t command_id, int32_t event_flags) override {}
   void Close() override {}
 
   DISALLOW_COPY_AND_ASSIGN(ListMenuShelfItemDelegate);
 };
 
 }  // namespace
 
 // Test fixture for testing material design ink drop ripples on shelf.
@@ skipping 1091 matching lines @@
   EXPECT_EQ(views::InkDropState::ACTIVATED,
             overflow_button_ink_drop_->GetTargetInkDropState());
   EXPECT_THAT(overflow_button_ink_drop_->GetAndResetRequestedStates(),
               IsEmpty());
 
   ASSERT_TRUE(test_api_->IsShowingOverflowBubble());
 }
 
 }  // namespace test
 }  // namespace ash