Remove all uses of the global Dispatcher Get function.

ipc/ipc_test_sink.h

 // Copyright (c) 2011 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_TEST_SINK_H_
 #define IPC_IPC_TEST_SINK_H_
 #pragma once
 
 #include <utility>
 #include <vector>
@@ skipping 24 matching lines @@
 //   // this: IPC_MESSAGE_ROUTED2(ViewMsg_Foo, bool, int)
 //   IPC::Message* msg = test_sink.GetFirstMessageMatching(ViewMsg_Foo::ID));
 //   ASSERT_TRUE(msg);
 //   bool first_param;
 //   int second_param;
 //   ViewMsg_Foo::Read(msg, &first_param, &second_param);
 //
 //   // Go on to the next phase of the test.
 //   test_sink.ClearMessages();
 //
+// To read a sync reply, do this:
+//
+//   IPC::Message* msg = test_sink.GetUniqueMessageMatching(IPC_REPLY_ID);
+//   ASSERT_TRUE(msg);
+//   TupleTypes<ViewHostMsg_Foo::ReplyParam>::ValueType reply_data;
+//   EXPECT_TRUE(ViewHostMsg_Foo::ReadReplyParam(msg, &reply_data));
+//
 // You can also register to be notified when messages are posted to the sink.
 // This can be useful if you need to wait for a particular message that will
 // be posted asynchronously.  Example usage:
 //
 //   class MyListener : public IPC::Channel::Listener {
 //    public:
 //     virtual bool OnMessageReceived(const IPC::Message& msg) {
 //       <do something with the message>
 //       MessageLoop::current()->Quit();
 //       return false;  // to store the message in the sink, or true to drop it
@@ skipping 59 matching lines @@
   // The actual list of received messages.
   std::vector<Message> messages_;
   ObserverList<Channel::Listener> filter_list_;
 
   DISALLOW_COPY_AND_ASSIGN(TestSink);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_TEST_SINK_H_