Fetch extension blacklist states from SafeBrowsing server

chrome/browser/extensions/crx_installer.cc

 // 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.
 
 #include "chrome/browser/extensions/crx_installer.h"
 
 #include <map>
 #include <set>
 
 #include "base/bind.h"
@@ skipping 505 matching lines @@
 }
 
 void CrxInstaller::OnBlacklistChecked(
     extensions::Blacklist::BlacklistState blacklist_state) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (!service_weak_)
     return;
 
   blacklist_state_ = blacklist_state;
 
-  if (blacklist_state_ == extensions::Blacklist::BLACKLISTED_MALWARE &&
+  if ((blacklist_state_ == extensions::Blacklist::BLACKLISTED_MALWARE ||
+       blacklist_state_ == extensions::Blacklist::BLACKLISTED_UNKNOWN) &&
       !allow_silent_install_) {
     // User tried to install a blacklisted extension. Show an error and
     // refuse to install it.
     ReportFailureFromUIThread(extensions::CrxInstallerError(
         l10n_util::GetStringFUTF16(IDS_EXTENSION_IS_BLACKLISTED,
                                    UTF8ToUTF16(extension()->name()))));
     UMA_HISTOGRAM_ENUMERATION("ExtensionBlacklist.BlockCRX",
                               extension()->location(),
                               Manifest::NUM_LOCATIONS);
     return;
@@ skipping 325 matching lines @@
   if (!prefs->DidExtensionEscalatePermissions(extension()->id()))
     return;
 
   if (client_) {
     AddRef();  // Balanced in InstallUIProceed() and InstallUIAbort().
     client_->ConfirmReEnable(this, extension());
   }
 }
 
 }  // namespace extensions