Use TaskScheduler instead of WorkerPool in file_ios.cc.

net/disk_cache/blockfile/file_ios.cc

Index: net/disk_cache/blockfile/file_ios.cc
diff --git a/net/disk_cache/blockfile/file_ios.cc b/net/disk_cache/blockfile/file_ios.cc
index 5c9a6fadab62de89e577b315827a7ee7c5253dff..47ff7f8edf9b142dbb9c1ee7502201dc565e6ad4 100644
--- a/net/disk_cache/blockfile/file_ios.cc
+++ b/net/disk_cache/blockfile/file_ios.cc
@@ -14,7 +14,7 @@
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/macros.h"
-#include "base/threading/worker_pool.h"
+#include "base/task_scheduler/post_task.h"
 #include "net/base/net_errors.h"
 #include "net/disk_cache/blockfile/in_flight_io.h"
 #include "net/disk_cache/disk_cache.h"
@@ -121,8 +121,12 @@ void FileInFlightIO::PostRead(disk_cache::File *file, void* buf, size_t buf_len,
       new FileBackgroundIO(file, buf, buf_len, offset, callback, this));
   file->AddRef();  // Balanced on OnOperationComplete()
 
-  base::WorkerPool::PostTask(FROM_HERE,
-      base::Bind(&FileBackgroundIO::Read, operation.get()), true);
+  base::PostTaskWithTraits(
+      FROM_HERE, base::TaskTraits()
+                     .WithShutdownBehavior(
+                         base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN)
+                     .MayBlock(),
+      base::Bind(&FileBackgroundIO::Read, operation.get()));
   OnOperationPosted(operation.get());
 }
 
@@ -133,8 +137,12 @@ void FileInFlightIO::PostWrite(disk_cache::File* file, const void* buf,
       new FileBackgroundIO(file, buf, buf_len, offset, callback, this));
   file->AddRef();  // Balanced on OnOperationComplete()
 
-  base::WorkerPool::PostTask(FROM_HERE,
-      base::Bind(&FileBackgroundIO::Write, operation.get()), true);
+  base::PostTaskWithTraits(
+      FROM_HERE, base::TaskTraits()
+                     .WithShutdownBehavior(
+                         base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN)
+                     .MayBlock(),
+      base::Bind(&FileBackgroundIO::Write, operation.get()));
   OnOperationPosted(operation.get());
 }