Add a unit test for resetting the app list on a reshow.

ui/app_list/test/app_list_test_model.cc

Index: ui/app_list/test/app_list_test_model.cc
diff --git a/ui/app_list/test/app_list_test_model.cc b/ui/app_list/test/app_list_test_model.cc
index 66d2a6924ea83f5d173d14645dbfa928425ff185..1f8ef4264e996bd95203c0cbda477efa2ee60b70 100644
--- a/ui/app_list/test/app_list_test_model.cc
+++ b/ui/app_list/test/app_list_test_model.cc
@@ -6,6 +6,8 @@
 
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/stringprintf.h"
+#include "grit/ui_resources.h"
+#include "ui/base/resource/resource_bundle.h"
 
 namespace app_list {
 namespace test {
@@ -20,7 +22,10 @@ AppListTestModel::AppListTestItem::AppListTestItem(
     AppListTestModel* model)
     : AppListItem(id),
       model_(model) {
+  ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
+  SetIcon(*rb.GetImageNamed(IDR_DEFAULT_FAVICON_32).ToImageSkia(), false);
 }
+
 AppListTestModel::AppListTestItem::~AppListTestItem() {
 }
 
@@ -54,7 +59,7 @@ AppListItem* AppListTestModel::AddItemToFolder(AppListItem* item,
 }
 
 void AppListTestModel::MoveItemToFolder(AppListItem* item,
-                                          const std::string& folder_id) {
+                                        const std::string& folder_id) {
   AppListModel::MoveItemToFolder(item, folder_id);
 }