Check USB device path access when prompting users to select a device.

chromeos/dbus/permission_broker_client.h

 // Copyright (c) 2012 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 CHROMEOS_DBUS_PERMISSION_BROKER_CLIENT_H_
 #define CHROMEOS_DBUS_PERMISSION_BROKER_CLIENT_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 18 matching lines @@
  public:
   // The ResultCallback is used for both the RequestPathAccess and
   // RequestUsbAccess methods. Its boolean parameter represents the result of
   // the operation that it was submitted alongside.
   typedef base::Callback<void(bool)> ResultCallback;
 
   ~PermissionBrokerClient() override;
 
   static PermissionBrokerClient* Create();
 
+  // CheckPathAccess requests a hint from the permission broker about whether
+  // a later call to RequestPathAccess will be successful. It presumes that
+  // the |interface_id| value passed to RequestPathAccess will be
+  // UsbDevicePermissionsData::ANY_INTERFACE).
+  virtual void CheckPathAccess(const std::string& path,
+                               const ResultCallback& callback) = 0;
+
   // RequestPathAccess requests access to a single device node identified by
   // |path|. If |interface_id| value is passed (different than
   // UsbDevicePermissionData::ANY_INTERFACE), the request will check if a
   // specific interface is claimed while requesting access.
   // This allows devices with multiple interfaces to be accessed even if
   // some of them are already claimed by kernel.
   virtual void RequestPathAccess(const std::string& path,
                                  int interface_id,
                                  const ResultCallback& callback) = 0;
 
@@ skipping 32 matching lines @@
  protected:
   PermissionBrokerClient();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PermissionBrokerClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_PERMISSION_BROKER_CLIENT_H_