Add MessagePipe interface. Use it in ChannelDispatcherBase.

In WebRTC data streams are message-based, so the message framing
mechanism use for the old protocol doesn't make sense for the
WebRTC-based protocol. The new MessagePipe represents an abstract
messaging channel. StreamMessagePipeAdapter implements framing for the
old protocol. A different MessagePipe is going to be used for
WebRTC-based protocol.

BUG=547158

Review URL: https://codereview.chromium.org/1649063003

Cr-Commit-Position: refs/heads/master@{#373340}

1 files changed, 7 insertions, 5 deletions

diff --git a/remoting/protocol/host_control_dispatcher.cc b/remoting/protocol/host_control_dispatcher.cc
index fb8aee9..627eb7e 100644
--- a/remoting/protocol/host_control_dispatcher.cc
+++ b/remoting/protocol/host_control_dispatcher.cc
@@ -6,11 +6,13 @@
 
 #include "base/callback_helpers.h"
 #include "net/socket/stream_socket.h"
+#include "remoting/base/compound_buffer.h"
 #include "remoting/base/constants.h"
 #include "remoting/proto/control.pb.h"
 #include "remoting/proto/internal.pb.h"
 #include "remoting/protocol/clipboard_stub.h"
 #include "remoting/protocol/host_stub.h"
+#include "remoting/protocol/message_pipe.h"
 #include "remoting/protocol/message_serialization.h"
 
 namespace remoting {
@@ -24,34 +26,34 @@ void HostControlDispatcher::SetCapabilities(
     const Capabilities& capabilities) {
   ControlMessage message;
   message.mutable_capabilities()->CopyFrom(capabilities);
-  writer()->Write(SerializeAndFrameMessage(message), base::Closure());
+  message_pipe()->Send(&message, base::Closure());
 }
 
 void HostControlDispatcher::SetPairingResponse(
     const PairingResponse& pairing_response) {
   ControlMessage message;
   message.mutable_pairing_response()->CopyFrom(pairing_response);
-  writer()->Write(SerializeAndFrameMessage(message), base::Closure());
+  message_pipe()->Send(&message, base::Closure());
 }
 
 void HostControlDispatcher::DeliverHostMessage(
     const ExtensionMessage& message) {
   ControlMessage control_message;
   control_message.mutable_extension_message()->CopyFrom(message);
-  writer()->Write(SerializeAndFrameMessage(control_message), base::Closure());
+  message_pipe()->Send(&control_message, base::Closure());
 }
 
 void HostControlDispatcher::InjectClipboardEvent(const ClipboardEvent& event) {
   ControlMessage message;
   message.mutable_clipboard_event()->CopyFrom(event);
-  writer()->Write(SerializeAndFrameMessage(message), base::Closure());
+  message_pipe()->Send(&message, base::Closure());
 }
 
 void HostControlDispatcher::SetCursorShape(
     const CursorShapeInfo& cursor_shape) {
   ControlMessage message;
   message.mutable_cursor_shape()->CopyFrom(cursor_shape);
-  writer()->Write(SerializeAndFrameMessage(message), base::Closure());
+  message_pipe()->Send(&message, base::Closure());
 }
 
 void HostControlDispatcher::OnIncomingMessage(