Add a manifest property declaring USB printers supported by an app.

device/usb/usb_device_filter.cc

 // 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.
 
 #include "device/usb/usb_device_filter.h"
 
 #include "base/values.h"
 #include "device/usb/usb_descriptors.h"
 #include "device/usb/usb_device.h"
 
@@ skipping 78 matching lines @@
     }
 
     if (!foundMatch) {
       return false;
     }
   }
 
   return true;
 }
 
-base::Value* UsbDeviceFilter::ToValue() const {
+scoped_ptr<base::Value> UsbDeviceFilter::ToValue() const {
   scoped_ptr<base::DictionaryValue> obj(new base::DictionaryValue());
 
   if (vendor_id_set_) {
     obj->SetInteger(kVendorIdKey, vendor_id_);
     if (product_id_set_) {
       obj->SetInteger(kProductIdKey, product_id_);
     }
   }
 
   if (interface_class_set_) {
     obj->SetInteger(kInterfaceClassKey, interface_class_);
     if (interface_subclass_set_) {
       obj->SetInteger(kInterfaceSubclassKey, interface_subclass_);
       if (interface_protocol_set_) {
         obj->SetInteger(kInterfaceProtocolKey, interface_protocol_);
       }
     }
   }
 
-  return obj.release();
+  return obj.Pass();
 }
 
 // static
 bool UsbDeviceFilter::MatchesAny(scoped_refptr<UsbDevice> device,
                                  const std::vector<UsbDeviceFilter>& filters) {
   for (std::vector<UsbDeviceFilter>::const_iterator i = filters.begin();
        i != filters.end();
        ++i) {
     if (i->Matches(device)) {
       return true;
     }
   }
   return false;
 }
 
 }  // namespace device