Merge ShelfItemDelegate::ItemSelected & LauncherItemDelegate::Activate.

ash/common/shelf/shelf_item_delegate.cc

Index: ash/common/shelf/shelf_item_delegate.cc
diff --git a/ash/common/shelf/shelf_item_delegate.cc b/ash/common/shelf/shelf_item_delegate.cc
new file mode 100644
index 0000000000000000000000000000000000000000..bc3ec8c37d451c058c20cdf8d031306edb4f6cf8
--- /dev/null
+++ b/ash/common/shelf/shelf_item_delegate.cc
@@ -0,0 +1,19 @@
+// Copyright 2017 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/common/shelf/shelf_item_delegate.h"
+
+#include "ui/display/types/display_constants.h"
+
+namespace ash {
+
+ShelfItemDelegate::ShelfItemDelegate() {}
+ShelfItemDelegate::~ShelfItemDelegate() {}
+
+ShelfAction ShelfItemDelegate::ItemSelectedBySource(ShelfLaunchSource source) {
+  return ItemSelected(ui::ET_UNKNOWN, ui::EF_NONE, display::kInvalidDisplayId,
+                      source);
+}
+
+}  // namespace ash