extensions: Cleanup class/struct fwd declarations

extensions/browser/api/usb/usb_api.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_API_USB_USB_API_H_
 #define EXTENSIONS_BROWSER_API_USB_USB_API_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "device/usb/usb_device.h"
 #include "device/usb/usb_device_filter.h"
 #include "device/usb/usb_device_handle.h"
 #include "extensions/browser/api/api_resource_manager.h"
 #include "extensions/browser/extension_function.h"
 #include "extensions/common/api/usb.h"
 #include "net/base/io_buffer.h"
 
 namespace extensions {
 
 class DevicePermissionEntry;
-class DevicePermissions;
 class DevicePermissionsPrompt;
 class DevicePermissionsManager;
-class UsbDeviceResource;
 
 class UsbPermissionCheckingFunction : public UIThreadExtensionFunction {
  protected:
   UsbPermissionCheckingFunction();
   ~UsbPermissionCheckingFunction() override;
 
   bool HasDevicePermission(scoped_refptr<device::UsbDevice> device);
   void RecordDeviceLastUsed();
 
  private:
@@ skipping 327 matching lines @@
 
   void OnComplete(bool success);
 
   std::unique_ptr<extensions::api::usb::ResetDevice::Params> parameters_;
 
   DISALLOW_COPY_AND_ASSIGN(UsbResetDeviceFunction);
 };
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_USB_USB_API_H_