Index: src/wp-admin/js/theme.js
===================================================================
--- src/wp-admin/js/theme.js	(revision 42028)
+++ src/wp-admin/js/theme.js	(working copy)
@@ -1347,12 +1347,12 @@
 			event.target.value = '';
 		}
 
-		// Note that doSearch is throttled.
+		// Since doSearch is debounced, it will only run when user input comes to a rest.
 		this.doSearch( event );
 	},
 
 	// Runs a search on the theme collection.
-	doSearch: _.throttle( function( event ) {
+	doSearch: _.debounce( function( event ) {
 		var options = {};
 
 		this.collection.doSearch( event.target.value.replace( /\+/g, ' ' ) );
@@ -1520,7 +1520,7 @@
 		this.doSearch( event.target.value );
 	},
 
-	doSearch: _.throttle( function( value ) {
+	doSearch: _.debounce( function( value ) {
 		var request = {};
 
 		// Don't do anything if the search terms haven't changed.