Refactoring of new IPC-only pepper implementation

ppapi/host/dispatch_host_message.h

Index: ppapi/host/dispatch_host_message.h
diff --git a/ppapi/host/dispatch_host_message.h b/ppapi/host/dispatch_host_message.h
index 3e60e577995811528325215c36fcc42acfae1f0a..d3a584116936ef443aa27b3bcfbf34adcdc7c4d7 100644
--- a/ppapi/host/dispatch_host_message.h
+++ b/ppapi/host/dispatch_host_message.h
@@ -2,14 +2,16 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ipc/ipc_message_macros.h"
-
 // This file provides infrastructure for dispatching host resource call
 // messages. Normal IPC message handlers can't take extra parameters or
 // return values. We want to take a HostMessageContext as a parameter and
 // also return the int32_t return value to the caller.
 
+#ifndef PPAPI_HOST_DISPATCH_HOST_MESSAGE_H_
+#define PPAPI_HOST_DISPATCH_HOST_MESSAGE_H_
+
 #include "base/profiler/scoped_profile.h"  // For TRACK_RUN_IN_IPC_HANDLER.
+#include "ipc/ipc_message_macros.h"
 #include "ppapi/c/pp_errors.h"
 
 namespace ppapi {
@@ -76,3 +78,5 @@ inline int32_t DispatchResourceCall(ObjT* obj, Method method,
 
 }  // namespace host
 }  // namespace ppapi
+
+#endif  // PPAPI_HOST_DISPATCH_HOST_MESSAGE_H_