[DevTools] Support multiple sessions in content/ domain handlers

content/browser/devtools/devtools_io_context.h

 // Copyright 2015 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_BROWSER_DEVTOOLS_DEVTOOLS_IO_CONTEXT_H_
+#define CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_IO_CONTEXT_H_
+
 #include <stddef.h>
 
 #include <map>
 
 #include "base/callback.h"
 #include "base/files/file.h"
 #include "base/memory/ref_counted_delete_on_sequence.h"
 #include "base/memory/ref_counted_memory.h"
 
 namespace content {
@@ skipping 39 matching lines @@
   scoped_refptr<Stream> GetByHandle(const std::string& handle);
   bool Close(const std::string& handle);
   void DiscardAllStreams();
 
  private:
   using StreamsMap = std::map<std::string, scoped_refptr<Stream>>;
   StreamsMap streams_;
 };
 
 }  // namespace content
+
+#endif  // CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_IO_CONTEXT_H_