Revert of Use TaskScheduler instead of WorkerPool in cache_util.cc.

net/disk_cache/backend_unittest.cc

Index: net/disk_cache/backend_unittest.cc
diff --git a/net/disk_cache/backend_unittest.cc b/net/disk_cache/backend_unittest.cc
index 14580c0512ea5d7646882fb08514da6b99e4580c..e92dd9b2f59ce8d07ee293ce6e536c16402ec1ce 100644
--- a/net/disk_cache/backend_unittest.cc
+++ b/net/disk_cache/backend_unittest.cc
@@ -14,7 +14,6 @@
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/test/mock_entropy_provider.h"
-#include "base/test/scoped_task_scheduler.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread_restrictions.h"
@@ -83,9 +82,6 @@
 // Tests that can run with different types of caches.
 class DiskCacheBackendTest : public DiskCacheTestWithCache {
  protected:
-  DiskCacheBackendTest()
-      : scoped_task_scheduler_(base::MessageLoop::current()) {}
-
   // Some utility methods:
 
   // Perform IO operations on the cache until there is pending IO.
@@ -153,9 +149,6 @@
   void BackendDisabledAPI();
 
   void BackendEviction();
-
- private:
-  base::test::ScopedTaskScheduler scoped_task_scheduler_;
 };
 
 int DiskCacheBackendTest::GeneratePendingIO(net::TestCompletionCallback* cb) {
@@ -2054,8 +2047,6 @@
 // blockfile caches.
 #if !defined(OS_ANDROID)
 TEST_F(DiskCacheTest, SimpleCacheControlJoin) {
-  base::test::ScopedTaskScheduler scoped_task_scheduler(
-      base::MessageLoop::current());
   base::Thread cache_thread("CacheThread");
   ASSERT_TRUE(cache_thread.StartWithOptions(
                   base::Thread::Options(base::MessageLoop::TYPE_IO, 0)));