Add getUserSelectedDevices to the USB extensions API.

extensions/browser/api/device_permissions_prompt.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 EXTENSIONS_BROWSER_DEVICE_PERMISSIONS_PROMPT_H_
 #define EXTENSIONS_BROWSER_DEVICE_PERMISSIONS_PROMPT_H_
 
 #include <vector>
 
 #include "base/callback.h"
@@ skipping 106 matching lines @@
   class Delegate {
    public:
     // Called with the list of selected USB devices.
     virtual void OnUsbDevicesChosen(
         const std::vector<scoped_refptr<device::UsbDevice>>& devices) = 0;
 
    protected:
     virtual ~Delegate() {}
   };
 
-  typedef base::Callback<void(content::WebContents*,
-                              DevicePermissionsPrompt::Delegate*,
-                              scoped_refptr<DevicePermissionsPrompt::Prompt>)>
-      ShowDialogCallback;
-
-  static ShowDialogCallback GetDefaultShowDialogCallback();
-
   DevicePermissionsPrompt(content::WebContents* web_contents);
   virtual ~DevicePermissionsPrompt();
 
-  virtual void AskForUsbDevices(
-      Delegate* delegate,
-      const Extension* extension,
-      content::BrowserContext* context,
-      bool multiple,
-      const std::vector<device::UsbDeviceFilter>& filters);
+  void AskForUsbDevices(Delegate* delegate,
+                        const Extension* extension,
+                        content::BrowserContext* context,
+                        bool multiple,
+                        const std::vector<device::UsbDeviceFilter>& filters);
+
+ protected:
+  virtual void ShowDialog() = 0;
+
+  content::WebContents* web_contents() { return web_contents_; }
+  Delegate* delegate() { return delegate_; }
+  scoped_refptr<Prompt> prompt() { return prompt_; }
 
  private:
   // Parent web contents of the device permissions UI dialog.
   content::WebContents* web_contents_;
 
   // The delegate called after the UI has been dismissed.
   Delegate* delegate_;
 
   // Parameters available to the UI implementation.
   scoped_refptr<Prompt> prompt_;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_DEVICE_PERMISSIONS_PROMPT_H_