[DevTools] Migrate from AgentStateCallbacks to DevToolsAgentHostObserver.

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 <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 {
 
 class BrowserContext;
 class RenderFrameHost;
 
 class CONTENT_EXPORT DevToolsManagerDelegate {
  public:
   // Opens the inspector for |agent_host|.
   virtual void Inspect(DevToolsAgentHost* agent_host);
 
-  virtual void DevToolsAgentStateChanged(DevToolsAgentHost* agent_host,
-                                         bool attached);
-
   // Returns DevToolsAgentHost type to use for given |host| target.
   virtual std::string GetTargetType(RenderFrameHost* host);
 
   // Returns DevToolsAgentHost title to use for given |host| target.
   virtual std::string GetTargetTitle(RenderFrameHost* host);
 
   // Returns DevToolsAgentHost title to use for given |host| target.
   virtual std::string GetTargetDescription(RenderFrameHost* host);
 
   // Returns all targets embedder would like to report as discoverable.
@@ skipping 16 matching lines @@
 
   // 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_