Update Windows It2Me to allow remote users to interact with elevated windows

remoting/host/win/elevation_helpers.cc

 // Copyright 2016 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 "remoting/host/win/elevation_helpers.h"
 
 #include <windows.h>
 
+#include "base/logging.h"
 #include "base/win/scoped_handle.h"
 
+namespace {
+
+void GetCurrentProcessToken(base::win::ScopedHandle* scoped_handle) {
+  DCHECK(scoped_handle);
+
+  HANDLE process_token;
+  OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &process_token);
+  scoped_handle->Set(process_token);
+  DCHECK(scoped_handle->IsValid());
+}
+
+}  // namespace
+
 namespace remoting {
 
 bool IsProcessElevated() {
-  HANDLE process_token;
-  OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &process_token);
-
-  base::win::ScopedHandle scoped_process_token(process_token);
+  base::win::ScopedHandle scoped_process_token;
+  GetCurrentProcessToken(&scoped_process_token);
 
   // Unlike TOKEN_ELEVATION_TYPE which returns TokenElevationTypeDefault when
-  // UAC is turned off, TOKEN_ELEVATION will tell you the process is elevated.
+  // UAC is turned off, TOKEN_ELEVATION returns whether the process is elevated.
   DWORD size;
   TOKEN_ELEVATION elevation;
-  GetTokenInformation(process_token, TokenElevation,
-                      &elevation, sizeof(elevation), &size);
+  if (!GetTokenInformation(scoped_process_token.Get(), TokenElevation,
+                           &elevation, sizeof(elevation), &size)) {
+    PLOG(ERROR) << "GetTokenInformation() failed";
+    return false;
+  }
   return elevation.TokenIsElevated != 0;
 }
 
+bool CurrentProcessHasUiAccess() {
+  base::win::ScopedHandle scoped_process_token;
+  GetCurrentProcessToken(&scoped_process_token);
+
+  DWORD size;
+  DWORD uiaccess_value = 0;
+  if (!GetTokenInformation(scoped_process_token.Get(), TokenUIAccess,
+                           &uiaccess_value, sizeof(uiaccess_value), &size)) {
+    PLOG(ERROR) << "GetTokenInformation() failed";
+    return false;
+  }
+  return uiaccess_value != 0;
+}
+
 }  // namespace remoting