Disable app list folders by default for non-ChromeOS platforms.

ui/app_list/views/apps_grid_view_unittest.cc

Index: ui/app_list/views/apps_grid_view_unittest.cc
diff --git a/ui/app_list/views/apps_grid_view_unittest.cc b/ui/app_list/views/apps_grid_view_unittest.cc
index 5e522e343398c96bf259037dab0fdc3ff07a1cba..f0d512e723bd2ac7c35028ca9f6e3ee4f244ce58 100644
--- a/ui/app_list/views/apps_grid_view_unittest.cc
+++ b/ui/app_list/views/apps_grid_view_unittest.cc
@@ -310,6 +310,7 @@ TEST_F(AppsGridViewTest, MouseDragWithFolderDisabled) {
 }
 
 TEST_F(AppsGridViewTest, MouseDragItemIntoFolder) {
+  CommandLine::ForCurrentProcess()->AppendSwitch(switches::kEnableFolderUI);
   size_t kTotalItems = 3;
   model_->PopulateApps(kTotalItems);
   EXPECT_EQ(model_->top_level_item_list()->item_count(), kTotalItems);
@@ -357,6 +358,7 @@ TEST_F(AppsGridViewTest, MouseDragItemIntoFolder) {
 }
 
 TEST_F(AppsGridViewTest, MouseDragMaxItemsInFolder) {
+  CommandLine::ForCurrentProcess()->AppendSwitch(switches::kEnableFolderUI);
   // Create and add a folder with 15 items in it.
   size_t kTotalItems = kMaxFolderItems - 1;
   model_->CreateAndPopulateFolderWithApps(kTotalItems);
@@ -403,6 +405,7 @@ TEST_F(AppsGridViewTest, MouseDragMaxItemsInFolder) {
 }
 
 TEST_F(AppsGridViewTest, MouseDragItemReorder) {
+  CommandLine::ForCurrentProcess()->AppendSwitch(switches::kEnableFolderUI);
   size_t kTotalItems = 2;
   model_->PopulateApps(kTotalItems);
   EXPECT_EQ(2u, model_->top_level_item_list()->item_count());
@@ -425,6 +428,7 @@ TEST_F(AppsGridViewTest, MouseDragItemReorder) {
 }
 
 TEST_F(AppsGridViewTest, MouseDragFolderReorder) {
+  CommandLine::ForCurrentProcess()->AppendSwitch(switches::kEnableFolderUI);
   size_t kTotalItems = 2;
   model_->CreateAndPopulateFolderWithApps(kTotalItems);
   model_->PopulateAppWithId(kTotalItems);