content/child: Remove use of MessageLoopProxy and deprecated MessageLoop APIs

content/child/thread_safe_sender.h

 // Copyright (c) 2013 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.
 
 #ifndef CONTENT_CHILD_THREAD_SAFE_SENDER_H_
 #define CONTENT_CHILD_THREAD_SAFE_SENDER_H_
 
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "ipc/ipc_sender.h"
 
 namespace base {
-class MessageLoopProxy;
+class SingleThreadTaskRunner;
 }
 
 namespace IPC {
 class SyncMessageFilter;
 }
 
 namespace content {
 class ChildThreadImpl;
 
 // The class of Sender returned by ChildThreadImpl::thread_safe_sender().
 class CONTENT_EXPORT ThreadSafeSender
     : public IPC::Sender,
       public base::RefCountedThreadSafe<ThreadSafeSender> {
  public:
   bool Send(IPC::Message* msg) override;
 
  protected:
-  ThreadSafeSender(const scoped_refptr<base::MessageLoopProxy>& main_loop,
-                   const scoped_refptr<IPC::SyncMessageFilter>& sync_filter);
+  ThreadSafeSender(
+      const scoped_refptr<base::SingleThreadTaskRunner>& main_task_runner,
+      const scoped_refptr<IPC::SyncMessageFilter>& sync_filter);
   ~ThreadSafeSender() override;
 
  private:
   friend class ChildThreadImpl;  // for construction
   friend class IndexedDBDispatcherTest;
   friend class WebIDBCursorImplTest;
   friend class base::RefCountedThreadSafe<ThreadSafeSender>;
 
-  scoped_refptr<base::MessageLoopProxy> main_loop_;
+  scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
   scoped_refptr<IPC::SyncMessageFilter> sync_filter_;
 
   DISALLOW_COPY_AND_ASSIGN(ThreadSafeSender);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_THREAD_SAFE_SENDER_H_