Add help link when Bluetooth adapter is off for WebBluetooth chooser

chrome/browser/chooser_controller/chooser_controller.h

 // Copyright 2016 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_CHOOSER_CONTROLLER_CHOOSER_CONTROLLER_H_
 #define CHROME_BROWSER_CHOOSER_CONTROLLER_CHOOSER_CONTROLLER_H_
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
 
@@ skipping 96 matching lines @@
   // Called when the user presses the 'Cancel' button in the dialog.
   virtual void Cancel() = 0;
 
   // Called when the user clicks outside the dialog or the dialog otherwise
   // closes without the user taking an explicit action.
   virtual void Close() = 0;
 
   // Open help center URL.
   virtual void OpenHelpCenterUrl() const = 0;
 
+  // Provide help information when the adapter is off.
+  virtual void OpenAdapterOffHelpUrl() const;
+
   // Only one view may be registered at a time.
   void set_view(View* view) { view_ = view; }
   View* view() const { return view_; }
 
  private:
   content::RenderFrameHost* const owning_frame_;
   const int title_string_id_origin_;
   const int title_string_id_extension_;
   View* view_ = nullptr;
 
   DISALLOW_COPY_AND_ASSIGN(ChooserController);
 };
 
 #endif  // CHROME_BROWSER_CHOOSER_CONTROLLER_CHOOSER_CONTROLLER_H_