[Aura] Implement views-based applist.

ui/aura_shell/app_list/app_list_item_model_observer.h

Index: ui/aura_shell/app_list/app_list_item_model_observer.h
diff --git a/ui/aura_shell/app_list/app_list_item_model_observer.h b/ui/aura_shell/app_list/app_list_item_model_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..f43d102f3d900238ca5f11d5b1904d9602e547e2
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+++ b/ui/aura_shell/app_list/app_list_item_model_observer.h
@@ -0,0 +1,27 @@
+// Copyright (c) 2011 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 UI_AURA_SHELL_APP_LIST_APP_LIST_ITEM_MODEL_OBSERVER_H_
+#define UI_AURA_SHELL_APP_LIST_APP_LIST_ITEM_MODEL_OBSERVER_H_
+#pragma once
+
+#include "ui/aura_shell/aura_shell_export.h"
+
+namespace aura_shell {
+
+class AURA_SHELL_EXPORT AppListItemModelObserver {
+ public:
+  // Invoked after app list item's icon is changed.
+  virtual void ItemIconChanged() = 0;
+
+  // Invoked after app list item's title is changed.
+  virtual void ItemTitleChanged() = 0;
+
+ protected:
+  virtual ~AppListItemModelObserver() {}
+};
+
+}  // namespace aura_shell
+
+#endif  // UI_AURA_SHELL_APP_LIST_APP_LIST_ITEM_MODEL_OBSERVER_H_