Replace uses of hash_map in //base

base/task/cancelable_task_tracker.cc

 // Copyright 2014 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.
 
 #include "base/task/cancelable_task_tracker.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 116 matching lines @@
   *is_canceled_cb =
       Bind(&IsCanceled, flag, Owned(untrack_and_delete_flag_runner));
 
   Track(id, flag);
   return id;
 }
 
 void CancelableTaskTracker::TryCancel(TaskId id) {
   DCHECK(sequence_checker_.CalledOnValidSequence());
 
-  hash_map<TaskId, CancellationFlag*>::const_iterator it = task_flags_.find(id);
+  const auto it = task_flags_.find(id);
   if (it == task_flags_.end()) {
     // Two possibilities:
     //
     //   1. The task has already been untracked.
     //   2. The TaskId is bad or unknown.
     //
     // Since this function is best-effort, it's OK to ignore these.
     return;
   }
   it->second->Set();
 }
 
 void CancelableTaskTracker::TryCancelAll() {
   DCHECK(sequence_checker_.CalledOnValidSequence());
-
-  for (hash_map<TaskId, CancellationFlag*>::const_iterator it =
-           task_flags_.begin();
-       it != task_flags_.end();
-       ++it) {
-    it->second->Set();
-  }
+  for (const auto it : task_flags_)

[Łukasz Anforowicz, 2017/04/24 18:46:10]

nit:s/const auto/const auto&/ ?

+    it.second->Set();
 }
 
 bool CancelableTaskTracker::HasTrackedTasks() const {
   DCHECK(sequence_checker_.CalledOnValidSequence());
   return !task_flags_.empty();
 }
 
 void CancelableTaskTracker::Track(TaskId id, CancellationFlag* flag) {
   DCHECK(sequence_checker_.CalledOnValidSequence());
-
   bool success = task_flags_.insert(std::make_pair(id, flag)).second;
   DCHECK(success);
 }
 
 void CancelableTaskTracker::Untrack(TaskId id) {
   DCHECK(sequence_checker_.CalledOnValidSequence());
   size_t num = task_flags_.erase(id);
   DCHECK_EQ(1u, num);
 }
 
 }  // namespace base