Add "clear" to about://instant.

chrome/browser/resources/instant/instant.js

 // Copyright 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.
 
 // Redefine '$' here rather than including 'cr.js', since this is
 // the only function needed.  This allows this file to be loaded
 // in a browser directly for layout and some testing purposes.
 var $ = function(id) { return document.getElementById(id); };
 
 /**
@@ skipping 103 matching lines @@
     if ($(prefName).type == 'checkbox')
       value = $(prefName).checked;
     else if ($(prefName).type == 'number')
       value = parseFloat($(prefName).value);
     else
       value = $(prefName).value;
     chrome.send('setPreferenceValue', [prefName, value]);
   }
 
   /**
-   * Handle processing of "Reset" button.
-   * Causes off form values to be updated based on current preference values.
-   */
-  function onReset() {
-    for (var i = 0; i < FIELDS.length; i++) {
-      var field = FIELDS[i];
-      if ($(field.key).type == 'checkbox')
-        $(field.key).checked = field.default;
-      else
-        $(field.key).value = field.default;
-      setPreferenceValue(field.key);
-    }
-    return false;
-  }
-
-  /**
    * Saves data back into Chrome preferences.
    */
   function onSave() {
     for (var i = 0; i < FIELDS.length; i++) {
       var field = FIELDS[i];
       setPreferenceValue(field.key);
     }
     return false;
   }
 
@@ skipping 13 matching lines @@
     for (var i = 0; i < info.entries.length; ++i) {
       var entry = info.entries[i];
       var row = createElementWithClass('p', 'debug');
       row.appendChild(createElementWithClass('span', 'timestamp')).textContent =
           entry.time;
       row.appendChild(document.createElement('span')).textContent = entry.text;
       $('instant-debug-info').appendChild(row);
     }
   }
 
+  /**
+   * Resets list of debug events.
+   */
+  function clearDebugInfo() {
+    $('instant-debug-info').innerHTML = '';
+    chrome.send('clearDebugInfo');
+  }
+
   function loadForm() {
     for (var i = 0; i < FIELDS.length; i++)
       getPreferenceValue(FIELDS[i].key);
   }
 
   /**
    * Build and initialize the configuration form.
    */
   function initialize() {
     buildForm();
     loadForm();
     initForm();
     getDebugInfo();
 
-    $('reset-button').onclick = onReset.bind(this);
     $('save-button').onclick = onSave.bind(this);
+    $('clear-button').onclick = clearDebugInfo.bind(this);
   }
 
   return {
     initialize: initialize,
     getDebugInfoResult: getDebugInfoResult,
     getPreferenceValueResult: getPreferenceValueResult
   };
 })();
 
 document.addEventListener('DOMContentLoaded', instantConfig.initialize);