Drastically reduce the number of redraws when editing content settings.

chrome/browser/resources/options/content_settings_exceptions_area.js

Index: chrome/browser/resources/options/content_settings_exceptions_area.js
diff --git a/chrome/browser/resources/options/content_settings_exceptions_area.js b/chrome/browser/resources/options/content_settings_exceptions_area.js
index da67d0131addabede11bb365230f1659978ec921..3f64ba4a423744d7b01fbac41ff869761ba61bd9 100644
--- a/chrome/browser/resources/options/content_settings_exceptions_area.js
+++ b/chrome/browser/resources/options/content_settings_exceptions_area.js
@@ -459,15 +459,23 @@ cr.define('options.contentSettings', function() {
 
     /**
      * Adds an exception to the js model.
-     * @param {Object} entry A dictionary of values for the exception.
+     * @param {Object} entries A list of dictionaries of values, each dictionary
+     *     represents an exception.
      */
-    addException: function(entry) {
+    addExceptions: function(entries) {
+      var insertIndex = this.dataModel.length;
+
       if (this.isEditable()) {
         // We have to add it before the Add New Exception row.
-        this.dataModel.splice(this.dataModel.length - 1, 0, entry);
-      } else {
-        this.dataModel.push(entry);
+        insertIndex = insertIndex - 1;
       }
+
+      var args = [insertIndex, 0];

[arv (Not doing code reviews), 2011/01/12 00:42:32]

more JS magic...

args.push.apply(args, entries);

or use unshift on entries

+      for (var i = 0; i < entries.length; i++) {
+        args.push(entries[i]);
+      }
+
+      this.dataModel.splice.apply(this.dataModel, args);
     },
 
     /**