extensions: tabs: set tab id to -1 for app/devtools windows

chrome/browser/extensions/extension_tab_util.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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_TAB_UTIL_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_TAB_UTIL_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 159 matching lines @@
   static void ForEachTab(
       const base::Callback<void(content::WebContents*)>& callback);
 
   static WindowController* GetWindowControllerOfTab(
       const content::WebContents* web_contents);
 
   // Open the extension's options page. Returns true if an options page was
   // successfully opened (though it may not necessarily *load*, e.g. if the
   // URL does not exist).
   static bool OpenOptionsPage(const Extension* extension, Browser* browser);
+
+  // Returns true if the given Browser can report tabs to extensions.
+  // Example of Browsers which don't support tabs include apps and devtools.
+  static bool BrowserSupportsTabs(Browser* browser);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_TAB_UTIL_H_