chrome: Cleanup class/struct forward declarations

chrome/browser/usb/web_usb_chooser_service.h

 // Copyright 2015 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_USB_WEB_USB_CHOOSER_SERVICE_H_
 #define CHROME_BROWSER_USB_WEB_USB_CHOOSER_SERVICE_H_
 
 #include <vector>
 
 #include "base/macros.h"
 #include "components/bubble/bubble_reference.h"
 #include "device/usb/public/interfaces/chooser_service.mojom.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "mojo/public/cpp/bindings/interface_request.h"
 
 namespace content {
 class RenderFrameHost;
 }
 
-namespace device {
-class UsbDevice;
-}
-
 // Implementation of the public device::usb::ChooserService interface.
 // This interface can be used by a webpage to request permission from user
 // to access a certain device.
 class WebUsbChooserService : public device::usb::ChooserService {
  public:
   explicit WebUsbChooserService(content::RenderFrameHost* render_frame_host);
 
   ~WebUsbChooserService() override;
 
   // device::usb::ChooserService:
   void GetPermission(std::vector<device::usb::DeviceFilterPtr> device_filters,
                      const GetPermissionCallback& callback) override;
 
   void Bind(mojo::InterfaceRequest<device::usb::ChooserService> request);
 
  private:
   content::RenderFrameHost* const render_frame_host_;
   mojo::BindingSet<device::usb::ChooserService> bindings_;
   std::vector<BubbleReference> bubbles_;
 
   DISALLOW_COPY_AND_ASSIGN(WebUsbChooserService);
 };
 
 #endif  // CHROME_BROWSER_USB_WEB_USB_CHOOSER_SERVICE_H_