diff -r 000000000000 -r 6474c204b198 ipc/chromium/src/base/worker_pool_mac.mm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ipc/chromium/src/base/worker_pool_mac.mm	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,72 @@
+// Copyright (c) 2008 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/worker_pool.h"
+
+#import <Foundation/Foundation.h>
+
+#include "base/logging.h"
+#import "base/singleton_objc.h"
+#include "base/task.h"
+
+// TaskOperation adapts Task->Run() for use in an NSOperationQueue.
+@interface TaskOperation : NSOperation {
+ @private
+  Task* task_;  // (strong)
+}
+
+// Returns an autoreleased instance of TaskOperation.  See -initWithTask: for
+// details.
++ (id)taskOperationWithTask:(Task*)task;
+
+// Designated initializer.  |task| is adopted as the Task* whose Run method
+// this operation will call when executed.
+- (id)initWithTask:(Task*)task;
+
+@end
+
+@implementation TaskOperation
+
++ (id)taskOperationWithTask:(Task*)task {
+  return [[[TaskOperation alloc] initWithTask:task] autorelease];
+}
+
+- (id)init {
+  return [self initWithTask:NULL];
+}
+
+- (id)initWithTask:(Task*)task {
+  if ((self = [super init])) {
+    task_ = task;
+  }
+  return self;
+}
+
+- (void)main {
+  DCHECK(task_) << "-[TaskOperation main] called with no task";
+  task_->Run();
+  delete task_;
+  task_ = NULL;
+}
+
+- (void)dealloc {
+  DCHECK(!task_) << "-[TaskOperation dealloc] called on unused TaskOperation";
+  delete task_;
+  [super dealloc];
+}
+
+@end
+
+bool WorkerPool::PostTask(const tracked_objects::Location& from_here,
+                          Task* task, bool task_is_slow) {
+  // Ignore |task_is_slow|, it doesn't map directly to any tunable aspect of
+  // an NSOperation.
+
+  task->SetBirthPlace(from_here);
+
+  NSOperationQueue* operation_queue = SingletonObjC<NSOperationQueue>::get();
+  [operation_queue addOperation:[TaskOperation taskOperationWithTask:task]];
+
+  return true;
+}