libchrome: Several upstreamable fixes from libchrome

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 21 matching lines @@
 }
 
 void RunIfNotCanceledThenUntrack(const CancellationFlag* flag,
                                  const Closure& task,
                                  const Closure& untrack) {
   RunIfNotCanceled(flag, task);
   untrack.Run();
 }
 
 bool IsCanceled(const CancellationFlag* flag,
-                base::ScopedClosureRunner* cleanup_runner) {
+                base::ScopedClosureRunner* /*cleanup_runner*/) {
   return flag->IsSet();
 }
 
 void RunAndDeleteFlag(const Closure& closure, const CancellationFlag* flag) {
   closure.Run();
   delete flag;
 }
 
 void RunOrPostToTaskRunner(TaskRunner* task_runner, const Closure& closure) {
   if (task_runner->RunsTasksOnCurrentThread())
@@ skipping 129 matching lines @@
   DCHECK(success);
 }
 
 void CancelableTaskTracker::Untrack(TaskId id) {
   DCHECK(thread_checker_.CalledOnValidThread());
   size_t num = task_flags_.erase(id);
   DCHECK_EQ(1u, num);
 }
 
 }  // namespace base