Remove deprecated methods TaskTraits::WithFileIO()/WithWait().

base/task_scheduler/task_traits.cc

Index: base/task_scheduler/task_traits.cc
diff --git a/base/task_scheduler/task_traits.cc b/base/task_scheduler/task_traits.cc
index 3cd6a61da69d2ada418db6e05f9d810f4a29be8b..580fdeb20b5d345c08a9b9e6bf705bc140958965 100644
--- a/base/task_scheduler/task_traits.cc
+++ b/base/task_scheduler/task_traits.cc
@@ -34,14 +34,6 @@ TaskTraits& TaskTraits::WithSyncPrimitives() {
   return *this;
 }
 
-TaskTraits& TaskTraits::WithFileIO() {
-  return MayBlock();
-}
-
-TaskTraits& TaskTraits::WithWait() {
-  return MayBlock().WithSyncPrimitives();
-}
-
 TaskTraits& TaskTraits::WithPriority(TaskPriority priority) {
   priority_ = priority;
   return *this;