Add path open errors from the permission broker to the device log.

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 <stdint.h>
 
 #include <string>
@@ skipping 16 matching lines @@
 class CHROMEOS_EXPORT PermissionBrokerClient : public DBusClient {
  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;
 
   // An OpenPathCallback callback is run when an OpenPath request is completed.
   typedef base::Callback<void(dbus::FileDescriptor)> OpenPathCallback;
 
+  // An ErrorCallback callback is run when an error is returned by the
+  // permission broker.
+  typedef base::Callback<void(const std::string& error_name,
+                              const std::string& message)>
+      ErrorCallback;
+
   ~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;
 
   // OpenPath requests that the permission broker open the device node
-  // identified by |path| and return the resulting file descriptor.
+  // identified by |path| and return the resulting file descriptor. One of
+  // |callback| or |error_callback| is called.
   virtual void OpenPath(const std::string& path,
-                        const OpenPathCallback& callback) = 0;
+                        const OpenPathCallback& callback,
+                        const ErrorCallback& error_callback) = 0;
 
   // Requests the |port| be opened on the firewall for incoming TCP/IP
   // connections received on |interface| (an empty string indicates all
   // interfaces). An open pipe must be passed as |lifeline_fd| so that the
   // permission broker can monitor the lifetime of the calling process.
   virtual void RequestTcpPortAccess(uint16_t port,
                                     const std::string& interface,
                                     const dbus::FileDescriptor& lifeline_fd,
                                     const ResultCallback& callback) = 0;
 
@@ skipping 23 matching lines @@
  protected:
   PermissionBrokerClient();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PermissionBrokerClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_PERMISSION_BROKER_CLIENT_H_