Eliminate Chromevox log spam.

chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js

 // Copyright 2014 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.
 
 /**
  * @fileoverview Provides output services for ChromeVox.
  */
 
 goog.provide('Output');
 goog.provide('Output.EventType');
@@ skipping 718 matching lines @@
       var output = new cvox.NavBraille({
         text: buff,
         startIndex: startIndex,
         endIndex: endIndex
       });
 
       cvox.ChromeVox.braille.write(output);
     }
 
     // Display.
-    chrome.accessibilityPrivate.setFocusRing(this.locations_);
+    if (cvox.ChromeVox.isChromeOS)
+      chrome.accessibilityPrivate.setFocusRing(this.locations_);
   },
 
   /**
    * Renders the given range using optional context previous range and event
    * type.
    * @param {!cursors.Range} range
    * @param {cursors.Range} prevRange
    * @param {chrome.automation.EventType|string} type
    * @param {!Array<Spannable>} buff Buffer to receive rendered output.
    * @private
@@ skipping 571 matching lines @@
             elem.end);
       });
       spansToRemove.forEach(result.removeSpan.bind(result));
       separator = Output.SPACE;
     });
     return result;
   }
 };
 
 });  // goog.scope