Fixes to possible GetLastError bugs

chrome/browser/password_manager/password_manager_util_win.cc

 // Copyright 2013 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.
 
 // windows.h must be first otherwise Win8 SDK breaks.
 #include <windows.h>
 #include <LM.h>
 #include <wincred.h>
 
 // SECURITY_WIN32 must be defined in order to get
@@ skipping 111 matching lines @@
     HANDLE handle = INVALID_HANDLE_VALUE;
 
     // Attempt to login using blank password.
     DWORD logon_result = LogonUser(username,
                                    L".",
                                    L"",
                                    LOGON32_LOGON_NETWORK,
                                    LOGON32_PROVIDER_DEFAULT,
                                    &handle);
 
+    auto last_error = GetLastError();

[brucedawson, 2015/09/12 00:33:55]

CloseHandle could affect LastError. Unlikely, but possible.

     // Win XP and later return ERROR_ACCOUNT_RESTRICTION for blank password.
     if (logon_result)
       CloseHandle(handle);
 
     // In the case the password is blank, then LogonUser returns a failure,
     // handle is INVALID_HANDLE_VALUE, and GetLastError() is
     // ERROR_ACCOUNT_RESTRICTION.
     // http://msdn.microsoft.com/en-us/library/windows/desktop/ms681385
     blank_password = (logon_result ||
-                      GetLastError() == ERROR_ACCOUNT_RESTRICTION);
+                      last_error == ERROR_ACCOUNT_RESTRICTION);
   }
 
   // Account for clock skew between pulling the password age and
   // writing to the preferences by adding a small skew factor here.
   last_changed += base::Time::kMicrosecondsPerSecond;
 
   // Update the preferences with new values.
   prefs->pref_last_changed_ = last_changed;
   prefs->blank_password_ = blank_password;
   return blank_password;
@@ skipping 162 matching lines @@
         }
       }
       SecureZeroMemory(password, sizeof(password));
     }
   } while (credErr == NO_ERROR &&
            (retval == false && tries < kMaxPasswordRetries));
   return retval;
 }
 
 }  // namespace password_manager_util_win