perf(jqLite): implement and use the `empty` method in place of `html(‘’)`

jQuery's elem.html('') is way slower than elem.empty(). As clearing
element contents happens quite often in certain scenarios, switching
to using .empty() provides a significant performance boost when using
Angular with jQuery.

Closes #4457

1 files changed, 2 insertions, 2 deletions

diff --git a/src/ng/compile.js b/src/ng/compile.js
index a6bcc3e7..0af76a75 100644
--- a/src/ng/compile.js
+++ b/src/ng/compile.js
@@ -1219,7 +1219,7 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
                                         });
           } else {
             $template = jqLite(jqLiteClone(compileNode)).contents();
-            $compileNode.html(''); // clear contents
+            $compileNode.empty(); // clear contents
             childTranscludeFn = compile($template, transcludeFn);
           }
         }
@@ -1651,7 +1651,7 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
               ? origAsyncDirective.templateUrl($compileNode, tAttrs)
               : origAsyncDirective.templateUrl;
 
-      $compileNode.html('');
+      $compileNode.empty();
 
       $http.get($sce.getTrustedResourceUrl(templateUrl), {cache: $templateCache}).
         success(function(content) {