Add new danger type for uncommon or unknown downloads.

chrome/browser/resources/downloads/downloads.js

 // 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.
 
 // TODO(jhawkins): Use hidden instead of showInline* and display:none.
 
 /**
  * Sets the display style of a node.
  */
 function showInline(node, isShow) {
@@ skipping 321 matching lines @@
   INTERRUPTED: 'INTERRUPTED',
 };
 
 /**
  * Explains why a download is in DANGEROUS state.
  */
 Download.DangerType = {
   NOT_DANGEROUS: 'NOT_DANGEROUS',
   DANGEROUS_FILE: 'DANGEROUS_FILE',
   DANGEROUS_URL: 'DANGEROUS_URL',
-  DANGEROUS_CONTENT: 'DANGEROUS_CONTENT'
-};
+  DANGEROUS_CONTENT: 'DANGEROUS_CONTENT',
+  UNCOMMON_CONTENT: 'UNCOMMON_CONTENT'
+}
 
 /**
  * Constants for the progress meter.
  */
 Download.Progress = {
   width: 48,
   height: 48,
   radius: 24,
   centerX: 24,
   centerY: 24,
@@ skipping 25 matching lines @@
 
   if (this.state_ == Download.States.DANGEROUS) {
     if (this.dangerType_ == Download.DangerType.DANGEROUS_FILE) {
       this.dangerDesc_.textContent = localStrings.getStringF('danger_file_desc',
                                                              this.fileName_);
     } else if (this.dangerType_ == Download.DangerType.DANGEROUS_URL) {
       this.dangerDesc_.textContent = localStrings.getString('danger_url_desc');
     } else if (this.dangerType_ == Download.DangerType.DANGEROUS_CONTENT) {
       this.dangerDesc_.textContent = localStrings.getStringF(
           'danger_content_desc', this.fileName_);
+    } else if (this.dangerType_ == Download.DangerType.UNCOMMON_CONTENT) {
+      this.dangerDesc_.textContent = localStrings.getStringF(
+          'danger_uncommon_desc', this.fileName_);
     }
     this.danger_.style.display = 'block';
     this.safe_.style.display = 'none';
   } else {
     downloads.scheduleIconLoad(this.nodeImg_,
                                'chrome://fileicon/' +
                                    encodeURIComponent(this.filePath_));
 
     if (this.state_ == Download.States.COMPLETE &&
         !this.fileExternallyRemoved_) {
@@ skipping 292 matching lines @@
     if (Date.now() - start > 50) {
       clearTimeout(resultsTimeout);
       resultsTimeout = setTimeout(tryDownloadUpdatedPeriodically, 5);
       break;
     }
   }
 }
 
 // Add handlers to HTML elements.
 window.addEventListener('DOMContentLoaded', load);