Extract debugger target enumeration into a separate class

content/browser/devtools/devtools_agent_host_impl.h

Index: content/browser/devtools/devtools_agent_host_impl.h
diff --git a/content/browser/devtools/devtools_agent_host_impl.h b/content/browser/devtools/devtools_agent_host_impl.h
index c3a52155f91294dd70f9fa3cab7d31f258eeff58..587c4f3e74dbdd9c29430cf8200c70a81e6d27c5 100644
--- a/content/browser/devtools/devtools_agent_host_impl.h
+++ b/content/browser/devtools/devtools_agent_host_impl.h
@@ -41,11 +41,21 @@ class CONTENT_EXPORT DevToolsAgentHostImpl : public DevToolsAgentHost {
     close_listener_ = listener;
   }
 
-  int id() { return id_; }
-
   // DevToolsAgentHost implementation.
+  virtual int id() OVERRIDE { return id_; }
+
   virtual RenderViewHost* GetRenderViewHost() OVERRIDE;
 
+  virtual bool attached() OVERRIDE;
+
+  virtual std::string title() OVERRIDE;
+
+  virtual GURL url() OVERRIDE;
+
+  virtual GURL thumbnail_url() OVERRIDE;
+
+  virtual GURL favicon_url() OVERRIDE;
+
  protected:
   DevToolsAgentHostImpl();
   virtual ~DevToolsAgentHostImpl() {}