Include USB printers in printer list as "provisional" devices.

extensions/common/api/printer_provider/usb_printer_manifest_data.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 EXTENSIONS_COMMON_API_PRINTER_PROVIDER_USB_PRINTER_MANIFEST_DATA_H_
 #define EXTENSIONS_COMMON_API_PRINTER_PROVIDER_USB_PRINTER_MANIFEST_DATA_H_
 
 #include <vector>
 
 #include "extensions/common/extension.h"
 
 namespace device {
+class UsbDevice;
 class UsbDeviceFilter;
 }
 
 namespace extensions {
 
 // The parsed form of the "usb_printers" manifest entry.
 class UsbPrinterManifestData : public Extension::ManifestData {
  public:
   UsbPrinterManifestData();
   ~UsbPrinterManifestData() override;
 
   // Gets the UsbPrinterManifestData for |extension|, or NULL if none was
   // specified.
   static const UsbPrinterManifestData* Get(const Extension* extension);
 
   // Parses the data stored in |value|. Sets |error| and returns an empty
   // scoped_ptr on failure.
   static scoped_ptr<UsbPrinterManifestData> FromValue(const base::Value& value,
                                                       base::string16* error);
 
+  bool SupportsDevice(const scoped_refptr<device::UsbDevice>& device) const;
+
   const std::vector<device::UsbDeviceFilter>& filters() const {
     return filters_;
   }
 
  private:
   std::vector<device::UsbDeviceFilter> filters_;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_API_PRINTER_PROVIDER_USB_PRINTER_MANIFEST_DATA_H_