[Win] Fix crash if the profile dir cannot be created

If the profile is NULL, the code will hit the CHECK on line 389 anyway.

BUG=414332

Review URL: https://codereview.chromium.org/878143003

Cr-Commit-Position: refs/heads/master@{#313709}

chrome/browser/chrome_browser_main.cc

@@ -364,7 +364,9 @@ Profile* CreatePrimaryProfile(const content::MainFunctionParams& parameters,
   // signed out, then we should show the user manager instead. By switching
   // the active profile to the guest profile we ensure that no
   // browser windows will be opened for the guest profile.
-  if (switches::IsNewProfileManagement() && !profile->IsGuestSession()) {
+  if (switches::IsNewProfileManagement() &&
+      profile &&
+      !profile->IsGuestSession()) {
     ProfileInfoCache& cache =
         g_browser_process->profile_manager()->GetProfileInfoCache();
     size_t profile_index = cache.GetIndexOfProfileWithPath(profile_path);