Protect AppListItemList Add/Remove and fix sync bugs

chrome/browser/ui/app_list/extension_app_model_builder.cc

Index: chrome/browser/ui/app_list/extension_app_model_builder.cc
diff --git a/chrome/browser/ui/app_list/extension_app_model_builder.cc b/chrome/browser/ui/app_list/extension_app_model_builder.cc
index 68ff0e866bdd9926e411f048d109abe3e276da69..4da5646c39540f90769fc825a576fcdb66cbbe2c 100644
--- a/chrome/browser/ui/app_list/extension_app_model_builder.cc
+++ b/chrome/browser/ui/app_list/extension_app_model_builder.cc
@@ -105,7 +105,7 @@ void ExtensionAppModelBuilder::OnDownloadProgress(
 
 void ExtensionAppModelBuilder::OnInstallFailure(
     const std::string& extension_id) {
-  model_->item_list()->DeleteItem(extension_id);
+  model_->DeleteItem(extension_id);
 }
 
 void ExtensionAppModelBuilder::OnExtensionLoaded(const Extension* extension) {
@@ -142,7 +142,7 @@ void ExtensionAppModelBuilder::OnExtensionUninstalled(
     service_->RemoveItem(extension->id());
     return;
   }
-  model_->item_list()->DeleteItem(extension->id());
+  model_->DeleteItem(extension->id());
 }
 
 void ExtensionAppModelBuilder::OnAppsReordered() {
@@ -191,9 +191,6 @@ void ExtensionAppModelBuilder::AddApps(
 }
 
 void ExtensionAppModelBuilder::BuildModel() {
-  // Delete any extension apps.
-  model_->item_list()->DeleteItemsByType(ExtensionAppItem::kItemType);
-

[jennyz, 2014/01/28 18:02:48]

Is the model_ empty, or we just don't need to clear the old data before building
model?

[stevenjb, 2014/01/28 18:28:08]

This only gets called once now. We used to call this when we changed profiles,
but that changed and this got left. I didn't want to maintain DeleteItemsByType
when we don't actually need it. I'll add some DCHECKs and remove the if
(tracker_) code to make this more clear.

   if (tracker_)
     tracker_->RemoveObserver(this);
 
@@ -225,7 +222,7 @@ void ExtensionAppModelBuilder::InsertApp(ExtensionAppItem* app) {
     service_->AddItem(app);
     return;
   }
-  model_->item_list()->AddItem(app);
+  model_->AddItem(app);
 }
 
 void ExtensionAppModelBuilder::SetHighlightedApp(