[device] Replace MessageLoopProxy usage with ThreadTaskRunnerHandle

device/serial/serial_io_handler.h

Index: device/serial/serial_io_handler.h
diff --git a/device/serial/serial_io_handler.h b/device/serial/serial_io_handler.h
index 5f93d63270b0ffcc8f4a31db94d21054a90a1a2c..6c66d5f75a98738fe7cd79c890dbcbd5691255ac 100644
--- a/device/serial/serial_io_handler.h
+++ b/device/serial/serial_io_handler.h
@@ -9,6 +9,8 @@
 #include "base/files/file.h"
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop_proxy.h"
+#include "base/single_thread_task_runner.h"
+#include "base/thread_task_runner_handle.h"
 #include "base/threading/non_thread_safe.h"
 #include "device/serial/buffer.h"
 #include "device/serial/serial.mojom.h"
@@ -24,8 +26,8 @@ class SerialIoHandler : public base::NonThreadSafe,
  public:
   // Constructs an instance of some platform-specific subclass.
   static scoped_refptr<SerialIoHandler> Create(
-      scoped_refptr<base::MessageLoopProxy> file_thread_message_loop,
-      scoped_refptr<base::MessageLoopProxy> ui_thread_message_loop);
+      scoped_refptr<base::SingleThreadTaskRunner> file_thread_message_loop,
+      scoped_refptr<base::SingleThreadTaskRunner> ui_thread_message_loop);
 
   typedef base::Callback<void(bool success)> OpenCompleteCallback;
 
@@ -84,8 +86,8 @@ class SerialIoHandler : public base::NonThreadSafe,
 
  protected:
   explicit SerialIoHandler(
-      scoped_refptr<base::MessageLoopProxy> file_thread_message_loop,
-      scoped_refptr<base::MessageLoopProxy> ui_thread_message_loop);
+      scoped_refptr<base::SingleThreadTaskRunner> file_thread_message_loop,
+      scoped_refptr<base::SingleThreadTaskRunner> ui_thread_message_loop);
   virtual ~SerialIoHandler();
 
   // Performs a platform-specific read operation. This must guarantee that
@@ -114,8 +116,8 @@ class SerialIoHandler : public base::NonThreadSafe,
   // Requests access to the underlying serial device, if needed.
   virtual void RequestAccess(
       const std::string& port,
-      scoped_refptr<base::MessageLoopProxy> file_message_loop,
-      scoped_refptr<base::MessageLoopProxy> ui_message_loop);
+      scoped_refptr<base::SingleThreadTaskRunner> file_message_loop,
+      scoped_refptr<base::SingleThreadTaskRunner> ui_message_loop);
 
   // Performs platform-specific, one-time port configuration on open.
   virtual bool PostOpen();
@@ -180,7 +182,7 @@ class SerialIoHandler : public base::NonThreadSafe,
 
   // Continues an Open operation on the FILE thread.
   void StartOpen(const std::string& port,
-                 scoped_refptr<base::MessageLoopProxy> io_message_loop);
+                 scoped_refptr<base::SingleThreadTaskRunner> io_message_loop);
 
   // Finalizes an Open operation (continued from StartOpen) on the IO thread.
   void FinishOpen(base::File file);
@@ -208,9 +210,9 @@ class SerialIoHandler : public base::NonThreadSafe,
   // Callback to handle the completion of a pending Open() request.
   OpenCompleteCallback open_complete_;
 
-  scoped_refptr<base::MessageLoopProxy> file_thread_message_loop_;
+  scoped_refptr<base::SingleThreadTaskRunner> file_thread_message_loop_;
   // On Chrome OS, PermissionBrokerClient should be called on the UI thread.
-  scoped_refptr<base::MessageLoopProxy> ui_thread_message_loop_;
+  scoped_refptr<base::SingleThreadTaskRunner> ui_thread_message_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(SerialIoHandler);
 };