Reset gaia given name upon signout

BUG=402050

Review URL: https://codereview.chromium.org/496853002

Cr-Commit-Position: refs/heads/master@{#291419}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@291419 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/profiles/gaia_info_update_service.cc

@@ -159,6 +159,7 @@ void GAIAInfoUpdateService::OnUsernameChanged(const std::string& username) {
   if (username.empty()) {
     // Unset the old user's GAIA info.
     cache.SetGAIANameOfProfileAtIndex(profile_index, base::string16());
+    cache.SetGAIAGivenNameOfProfileAtIndex(profile_index, base::string16());
     // The profile index may have changed.
     profile_index = cache.GetIndexOfProfileWithPath(profile_->GetPath());
     if (profile_index == std::string::npos)