Don't prompt to save malicious downloads on exit

chrome/browser/download/download_item_model.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/download/download_item_model.h"
 
 #include "base/i18n/number_formatting.h"
 #include "base/i18n/rtl.h"
 #include "base/metrics/field_trial.h"
 #include "base/strings/string16.h"
@@ skipping 419 matching lines @@
       // We shouldn't get any of these due to the IsDangerous() test above.
       NOTREACHED();
       // Fallthrough.
     case content::DOWNLOAD_DANGER_TYPE_DANGEROUS_FILE:
       return false;
   }
   NOTREACHED();
   return false;
 }
 
+// If you change this definition of malicious, also update
+// DownloadManagerImpl::NonMaliciousInProgressCount.
 bool DownloadItemModel::IsMalicious() const {
   if (!MightBeMalicious())
     return false;
   switch (download_->GetDangerType()) {
     case content::DOWNLOAD_DANGER_TYPE_DANGEROUS_URL:
     case content::DOWNLOAD_DANGER_TYPE_DANGEROUS_CONTENT:
     case content::DOWNLOAD_DANGER_TYPE_DANGEROUS_HOST:
       return true;
 
     case content::DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS:
@@ skipping 146 matching lines @@
   }
 
   // In progress download with no known time left and non-zero completed bytes:
   // "100/120 MB" or "100 MB"
   if (GetCompletedBytes() > 0)
     return size_ratio;
 
   // Instead of displaying "0 B" we say "Starting..."
   return l10n_util::GetStringUTF16(IDS_DOWNLOAD_STATUS_STARTING);
 }