Warn users about potentially unwanted 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.
  * @param {!Element} node The target element to show or hide.
  * @param {boolean} isShow Should the target element be visible.
@@ skipping 368 matching lines @@
 
 /**
  * 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',
   UNCOMMON_CONTENT: 'UNCOMMON_CONTENT',
-  DANGEROUS_HOST: 'DANGEROUS_HOST'
+  DANGEROUS_HOST: 'DANGEROUS_HOST',
+  POTENTIALLY_UNWANTED: 'POTENTIALLY_UNWANTED',
 };
 
 /**
  * Constants for the progress meter.
  */
 
 Download.Progress = (function() {
   var scale = window.devicePixelRatio;
   return {
     width: 48 * scale,
@@ skipping 35 matching lines @@
                                                              this.fileName_);
     } else if (this.dangerType_ == Download.DangerType.DANGEROUS_URL) {
       this.dangerDesc_.textContent = loadTimeData.getString('danger_url_desc');
     } else if (this.dangerType_ == Download.DangerType.DANGEROUS_CONTENT ||
                this.dangerType_ == Download.DangerType.DANGEROUS_HOST) {
       this.dangerDesc_.textContent = loadTimeData.getStringF(
           'danger_content_desc', this.fileName_);
     } else if (this.dangerType_ == Download.DangerType.UNCOMMON_CONTENT) {
       this.dangerDesc_.textContent = loadTimeData.getStringF(
           'danger_uncommon_desc', this.fileName_);
+    } else if (this.dangerType_ == Download.DangerType.POTENTIALLY_UNWANTED) {
+      this.dangerDesc_.textContent = loadTimeData.getStringF(
+          'danger_potentially_unwanted_desc', this.fileName_);
     }
     this.danger_.style.display = 'block';
     this.safe_.style.display = 'none';
   } else {
     downloads.scheduleIconLoad(this.nodeImg_,
                                'chrome://fileicon/' +
                                    encodeURIComponent(this.filePath_) +
                                    '?scale=' + window.devicePixelRatio + 'x');
 
     if (this.state_ == Download.States.COMPLETE &&
@@ skipping 329 matching lines @@
     if (Date.now() - start > 50) {
       clearTimeout(resultsTimeout);
       resultsTimeout = setTimeout(tryDownloadUpdatedPeriodically, 5);
       break;
     }
   }
 }
 
 // Add handlers to HTML elements.
 window.addEventListener('DOMContentLoaded', load);