Provide a Mojo equivalent of ThreadSafeSender.

ipc/ipc_channel_proxy.h

 // Copyright (c) 2012 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 IPC_IPC_CHANNEL_PROXY_H_
 #define IPC_IPC_CHANNEL_PROXY_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 212 matching lines @@
         mojo::GetProxy(proxy, GetAssociatedGroup());
     GetGenericRemoteAssociatedInterface(Interface::Name_, request.PassHandle());
   }
 
 #if defined(ENABLE_IPC_FUZZER)
   void set_outgoing_message_filter(OutgoingMessageFilter* filter) {
     outgoing_message_filter_ = filter;
   }
 #endif
 
+  using RunOnIOThreadCallback = base::Callback<void(Channel*)>;
+  // Invokes |callback| on the IO (IPC) thread.
+  void RunOnIOThread(const RunOnIOThreadCallback& callback);
+
   // Called to clear the pointer to the IPC task runner when it's going away.
   void ClearIPCTaskRunner();
 
  protected:
   class Context;
   // A subclass uses this constructor if it needs to add more information
   // to the internal state.
   explicit ChannelProxy(Context* context);
 
-
   // Used internally to hold state that is referenced on the IPC thread.
   class Context : public base::RefCountedThreadSafe<Context>,
                   public Listener {
    public:
     Context(Listener* listener,
             const scoped_refptr<base::SingleThreadTaskRunner>& ipc_thread);
     void ClearIPCTaskRunner();
     base::SingleThreadTaskRunner* ipc_task_runner() const {
       return ipc_task_runner_.get();
     }
@@ skipping 44 matching lines @@
     friend class ChannelProxy;
     friend class IpcSecurityTestUtil;
 
     // Create the Channel
     void CreateChannel(std::unique_ptr<ChannelFactory> factory);
 
     // Methods called on the IO thread.
     void OnSendMessage(std::unique_ptr<Message> message_ptr);
     void OnAddFilter();
     void OnRemoveFilter(MessageFilter* filter);
+    void RunWithChannel(const RunOnIOThreadCallback& callback);
 
     // Methods called on the listener thread.
     void AddFilter(MessageFilter* filter);
     void OnDispatchConnected();
     void OnDispatchError();
     void OnDispatchBadMessage(const Message& message);
     void OnDispatchAssociatedInterfaceRequest(
         const std::string& interface_name,
         mojo::ScopedInterfaceEndpointHandle handle);
 
@@ skipping 86 matching lines @@
   bool did_init_;
 
 #if defined(ENABLE_IPC_FUZZER)
   OutgoingMessageFilter* outgoing_message_filter_;
 #endif
 };
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_CHANNEL_PROXY_H_