DevTools: allow embedder handling async remote debugger commands.

content/public/browser/devtools_manager_delegate.h

 // Copyright 2014 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_PUBLIC_BROWSER_DEVTOOLS_MANAGER_DELEGATE_H_
 #define CONTENT_PUBLIC_BROWSER_DEVTOOLS_MANAGER_DELEGATE_H_
 
+#include <memory>
 #include <string>
+
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/devtools_agent_host.h"
 #include "url/gurl.h"
 
 namespace base {
 class DictionaryValue;
 }
 
 namespace content {
@@ skipping 21 matching lines @@
       const DevToolsAgentHost::DiscoveryCallback& callback);
 
   // Creates new inspectable target given the |url|.
   virtual scoped_refptr<DevToolsAgentHost> CreateNewTarget(const GURL& url);
 
   // Result ownership is passed to the caller.
   virtual base::DictionaryValue* HandleCommand(
       DevToolsAgentHost* agent_host,
       base::DictionaryValue* command);
 
+  using CommandCallback =
+      base::Callback<void(std::unique_ptr<base::DictionaryValue> response)>;
+  virtual bool HandleAsyncCommand(DevToolsAgentHost* agent_host,
+                                  base::DictionaryValue* command,
+                                  CommandCallback callback);
   // Should return discovery page HTML that should list available tabs
   // and provide attach links.
   virtual std::string GetDiscoveryPageHTML();
 
   // Returns frontend resource data by |path|.
   virtual std::string GetFrontendResource(const std::string& path);
 
   virtual ~DevToolsManagerDelegate();
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_DEVTOOLS_MANAGER_DELEGATE_H_