Rewrite base::Bind into base::BindOnce on trivial cases in base

base/observer_list_threadsafe.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_OBSERVER_LIST_THREADSAFE_H_
 #define BASE_OBSERVER_LIST_THREADSAFE_H_
 
 #include <algorithm>
 #include <map>
 #include <memory>
@@ skipping 133 matching lines @@
               Method m, Params&&... params) {
     Callback<void(ObserverType*)> method =
         Bind(&internal::Dispatcher<ObserverType, Method>::Run,
              m, std::forward<Params>(params)...);
 
     AutoLock lock(list_lock_);
     for (const auto& entry : observer_lists_) {
       ObserverListContext* context = entry.second.get();
       context->task_runner->PostTask(
           from_here,
-          Bind(&ObserverListThreadSafe<ObserverType>::NotifyWrapper,
-               this, context, method));
+          BindOnce(&ObserverListThreadSafe<ObserverType>::NotifyWrapper, this,
+                   context, method));
     }
   }
 
  private:
   friend class RefCountedThreadSafe<ObserverListThreadSafe<ObserverType>>;
 
   struct ObserverListContext {
     explicit ObserverListContext(NotificationType type)
         : task_runner(ThreadTaskRunnerHandle::Get()), list(type) {}
 
@@ skipping 53 matching lines @@
       observer_lists_;
 
   const NotificationType type_;
 
   DISALLOW_COPY_AND_ASSIGN(ObserverListThreadSafe);
 };
 
 }  // namespace base
 
 #endif  // BASE_OBSERVER_LIST_THREADSAFE_H_