Remove AppListItemListObserver from AppListModelBuilder.

The interface is not used.

Bug: 733662
Change-Id: I06667c7d5880bbe7bd1f82c69a8c3184625096fa
Reviewed-on: https://chromium-review.googlesource.com/783653Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Jiaquan He <hejq@google.com>
Cr-Commit-Position: refs/heads/master@{#518417}

chrome/browser/ui/app_list/app_list_model_builder.cc

@@ -5,6 +5,7 @@
 #include "chrome/browser/ui/app_list/app_list_model_builder.h"
 
 #include <utility>
+#include <vector>
 
 #include "ash/app_list/model/app_list_item.h"
 #include "ash/app_list/model/app_list_model.h"
@@ -17,8 +18,6 @@ AppListModelBuilder::AppListModelBuilder(AppListControllerDelegate* controller,
 }
 
 AppListModelBuilder::~AppListModelBuilder() {
-  if (!service_)
-    model_->top_level_item_list()->RemoveObserver(this);
 }
 
 void AppListModelBuilder::InitializeWithService(
@@ -36,7 +35,6 @@ void AppListModelBuilder::InitializeWithProfile(Profile* profile,
                                                 app_list::AppListModel* model) {
   DCHECK(!service_ && !profile_);
   model_ = model;
-  model_->top_level_item_list()->AddObserver(this);
   profile_ = profile;
 
   BuildModel();

chrome/browser/ui/app_list/app_list_model_builder.h

@@ -5,9 +5,9 @@
 #ifndef CHROME_BROWSER_UI_APP_LIST_APP_LIST_MODEL_BUILDER_H_
 #define CHROME_BROWSER_UI_APP_LIST_APP_LIST_MODEL_BUILDER_H_
 
+#include <memory>
 #include <string>
 
-#include "ash/app_list/model/app_list_item_list_observer.h"
 #include "ash/app_list/model/app_list_model.h"
 #include "base/macros.h"
 #include "chrome/browser/ui/app_list/app_list_syncable_service.h"
@@ -17,12 +17,12 @@ class Profile;
 
 // This abstract class populates and maintains the given |model| with
 // information from |profile| for the specific item type.
-class AppListModelBuilder : public app_list::AppListItemListObserver {
+class AppListModelBuilder {
  public:
   // |controller| is owned by implementation of AppListService.
   AppListModelBuilder(AppListControllerDelegate* controller,
                       const char* item_type);
-   ~AppListModelBuilder() override;
+  virtual ~AppListModelBuilder();
 
   // Initialize to use app-list sync and sets |service_| to |service|.
   // |service| is the owner of this instance and |model|.

chrome/browser/ui/app_list/arc/arc_app_model_builder.cc

@@ -4,6 +4,8 @@
 
 #include "chrome/browser/ui/app_list/arc/arc_app_model_builder.h"
 
+#include <vector>
+
 #include "base/memory/ptr_util.h"
 #include "chrome/browser/chromeos/arc/arc_util.h"
 #include "chrome/browser/profiles/profile.h"
@@ -83,11 +85,3 @@ void ArcAppModelBuilder::OnAppNameUpdated(const std::string& app_id,
 
   app_item->SetName(name);
 }
-
-void ArcAppModelBuilder::OnListItemMoved(size_t from_index,
-                                         size_t to_index,
-                                         app_list::AppListItem* item) {
-  // On ChromeOS we expect that ArcAppModelBuilder is initialized with
-  // AppListSyncableService and in this case this observer is not used.
-  NOTREACHED();
-}

chrome/browser/ui/app_list/arc/arc_app_model_builder.h

@@ -37,11 +37,6 @@ class ArcAppModelBuilder : public AppListModelBuilder,
   void OnAppNameUpdated(const std::string& app_id,
                         const std::string& name) override;
 
-  // AppListItemListObserver.
-  void OnListItemMoved(size_t from_index,
-                       size_t to_index,
-                       app_list::AppListItem* item) override;
-
   std::unique_ptr<ArcAppItem> CreateApp(const std::string& app_id,
                                         const ArcAppListPrefs::AppInfo& info);