Request file icon at current device scale factor.

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 397 matching lines @@
           'danger_content_desc', this.fileName_);
     } else if (this.dangerType_ == Download.DangerType.UNCOMMON_CONTENT) {
       this.dangerDesc_.textContent = loadTimeData.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_));
+                                   encodeURIComponent(this.filePath_) +
+                                   '?scale=' + window.devicePixelRatio + 'x');
 
     if (this.state_ == Download.States.COMPLETE &&
         !this.fileExternallyRemoved_) {
       this.nodeFileLink_.textContent = this.fileName_;
       this.nodeFileLink_.href = this.fileUrl_;
       this.nodeFileLink_.oncontextmenu = null;
     } else if (this.nodeFileName_.textContent != this.fileName_) {
       this.nodeFileName_.textContent = this.fileName_;
     }
     if (this.state_ == Download.States.INTERRUPTED)
@@ skipping 286 matching lines @@
     if (Date.now() - start > 50) {
       clearTimeout(resultsTimeout);
       resultsTimeout = setTimeout(tryDownloadUpdatedPeriodically, 5);
       break;
     }
   }
 }
 
 // Add handlers to HTML elements.
 window.addEventListener('DOMContentLoaded', load);