Allow chrome.debugger API to attach to extension background pages.

chrome/browser/extensions/api/debugger/debugger_api.h

 // Copyright (c) 2012 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.
 
 // Defines the Chrome Extensions Debugger API functions for attaching debugger
 // to the page.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_DEBUGGER_DEBUGGER_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_DEBUGGER_DEBUGGER_API_H_
 
@@ skipping 15 matching lines @@
 }
 
 class DebuggerFunction : public AsyncExtensionFunction {
  protected:
   DebuggerFunction();
   virtual ~DebuggerFunction() {}
 
   bool InitWebContents();
   bool InitClientHost();
 
+  void FormatErrorMessage(const std::string& format);
+
   content::WebContents* contents_;
-  int tab_id_;
+  int debuggee_tab_id_;
+  std::string debuggee_extension_id_;
   ExtensionDevToolsClientHost* client_host_;
 };
 
 // Implements the debugger.attach() extension function.
 class DebuggerAttachFunction : public DebuggerFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("debugger.attach", DEBUGGER_ATTACH)
 
   DebuggerAttachFunction();
 
@@ skipping 27 matching lines @@
   void SendResponseBody(base::DictionaryValue* result);
 
  protected:
   virtual ~DebuggerSendCommandFunction();
 
   // ExtensionFunction:
   virtual bool RunImpl() OVERRIDE;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_DEBUGGER_DEBUGGER_API_H_