Remove usage of WorkerPool from test_completion_callback_unittest.cc.

net/base/test_completion_callback_unittest.cc

Index: net/base/test_completion_callback_unittest.cc
diff --git a/net/base/test_completion_callback_unittest.cc b/net/base/test_completion_callback_unittest.cc
index a2bc49092ddd4b41004da6a4e38db924bfff8c90..db62f7e6ae32559dd12aa54e9cc8c753834a945e 100644
--- a/net/base/test_completion_callback_unittest.cc
+++ b/net/base/test_completion_callback_unittest.cc
@@ -2,15 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Illustrates how to use worker threads that issue completion callbacks
+// Illustrates how to use net::TestCompletionCallback.
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/macros.h"
-#include "base/message_loop/message_loop.h"
 #include "base/single_thread_task_runner.h"
-#include "base/threading/worker_pool.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "net/base/completion_callback.h"
 #include "net/base/test_completion_callback.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -38,9 +37,8 @@ class ExampleEmployer {
   ExampleEmployer();
   ~ExampleEmployer();
 
-  // Do some imaginary work on a worker thread;
-  // when done, worker posts callback on the original thread.
-  // Returns true on success
+  // Posts to the current thread a task which itself posts |callback| to the
+  // current thread. Returns true on success
   bool DoSomething(const CompletionCallback& callback);
 
  private:
@@ -50,14 +48,12 @@ class ExampleEmployer {
   DISALLOW_COPY_AND_ASSIGN(ExampleEmployer);
 };
 
-// Helper class; this is how ExampleEmployer puts work on a different thread
+// Helper class; this is how ExampleEmployer schedules work.
 class ExampleEmployer::ExampleWorker
     : public base::RefCountedThreadSafe<ExampleWorker> {
  public:
   ExampleWorker(ExampleEmployer* employer, const CompletionCallback& callback)
-      : employer_(employer),
-        callback_(callback),
-        origin_loop_(base::MessageLoop::current()) {}
+      : employer_(employer), callback_(callback) {}
   void DoWork();
   void DoCallback();
  private:
@@ -69,23 +65,15 @@ class ExampleEmployer::ExampleWorker
   ExampleEmployer* employer_;
   CompletionCallback callback_;
   // Used to post ourselves onto the origin thread.
-  base::Lock origin_loop_lock_;
-  base::MessageLoop* origin_loop_;
+  const scoped_refptr<base::SingleThreadTaskRunner> origin_task_runner_ =
+      base::ThreadTaskRunnerHandle::Get();
 };
 
 void ExampleEmployer::ExampleWorker::DoWork() {
-  // Running on the worker thread
   // In a real worker thread, some work would be done here.
   // Pretend it is, and send the completion callback.
-
-  // The origin loop could go away while we are trying to post to it, so we
-  // need to call its PostTask method inside a lock.  See ~ExampleEmployer.
-  {
-    base::AutoLock locked(origin_loop_lock_);
-    if (origin_loop_)
-      origin_loop_->task_runner()->PostTask(
-          FROM_HERE, base::Bind(&ExampleWorker::DoCallback, this));
-  }
+  origin_task_runner_->PostTask(FROM_HERE,
+                                base::Bind(&ExampleWorker::DoCallback, this));
 }
 
 void ExampleEmployer::ExampleWorker::DoCallback() {
@@ -110,9 +98,8 @@ bool ExampleEmployer::DoSomething(const CompletionCallback& callback) {
 
   request_ = new ExampleWorker(this, callback);
 
-  // Dispatch to worker thread...
-  if (!base::WorkerPool::PostTask(
-          FROM_HERE, base::Bind(&ExampleWorker::DoWork, request_), true)) {
+  if (!base::ThreadTaskRunnerHandle::Get()->PostTask(
+          FROM_HERE, base::Bind(&ExampleWorker::DoWork, request_))) {
     NOTREACHED();
     request_ = NULL;
     return false;