app_list: Enable level 1 of cpplint, be stricker.

ui/app_list/views/apps_grid_view.cc

Index: ui/app_list/views/apps_grid_view.cc
diff --git a/ui/app_list/views/apps_grid_view.cc b/ui/app_list/views/apps_grid_view.cc
index f5e5ca07aeafda5be94ecd226d34f44a617f7347..bc200c6bcc63d4757793fd8a317805db4c28bd22 100644
--- a/ui/app_list/views/apps_grid_view.cc
+++ b/ui/app_list/views/apps_grid_view.cc
@@ -291,14 +291,11 @@ class SynchronousDrag : public ui::DragSourceWin {
 
  private:
   // Overridden from ui::DragSourceWin.
-  virtual void OnDragSourceCancel() override {
-    canceled_ = true;
-  }
+  void OnDragSourceCancel() override { canceled_ = true; }
 
-  virtual void OnDragSourceDrop() override {
-  }
+  void OnDragSourceDrop() override {}
 
-  virtual void OnDragSourceMove() override {
+  void OnDragSourceMove() override {
     grid_view_->UpdateDrag(AppsGridView::MOUSE, GetCursorInGridViewCoords());
   }