perf($compile): avoid needless overhead when wrapping text nodes

This commit positively affects performance in two main ways:

1,  When wrapping text nodes in the compile step, we do not need the overhead
of the `forEach` function versus a normal for loop since we do not make
use of the closure for anything.

2.  When actually wrapping the node, we can completely bypass jqLite which
avoids several function calls and the overhead of cloning the wrapper node
which we already know to be unique.

Tests in applications show about an 83% decrease in time spent in this
specific loop.

Author: dcherman

src/.jshintrc

@@ -140,6 +140,7 @@
     "jqLiteInheritedData": false,
     "jqLiteBuildFragment": false,
     "jqLiteParseHTML": false,
+    "jqLiteWrapNode": false,
     "getBooleanAttrName": false,
     "getAliasedAttrName": false,
     "createEventHandler": false,

src/jqLite.js

@@ -248,6 +248,16 @@ function jqLiteParseHTML(html, context) {
   return [];
 }
 
+function jqLiteWrapNode(node, wrapper) {
+  var parent = node.parentNode;
+
+  if (parent) {
+    parent.replaceChild(wrapper, node);
+  }
+
+  wrapper.appendChild(node);
+}
+
 
 // IE9-11 has no method "contains" in SVG element and in Node.prototype. Bug #10259.
 var jqLiteContains = Node.prototype.contains || function(arg) {
@@ -939,12 +949,7 @@ forEach({
   },
 
   wrap: function(element, wrapNode) {
-    wrapNode = jqLite(wrapNode).eq(0).clone()[0];
-    var parent = element.parentNode;
-    if (parent) {
-      parent.replaceChild(wrapNode, element);
-    }
-    wrapNode.appendChild(element);
+    jqLiteWrapNode(element, jqLite(wrapNode).eq(0).clone()[0]);
   },
 
   remove: jqLiteRemove,

src/ng/compile.js

@@ -1299,13 +1299,19 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
         // modify it.
         $compileNodes = jqLite($compileNodes);
       }
+
+      var NOT_EMPTY = /\S+/;
+
       // We can not compile top level text elements since text nodes can be merged and we will
       // not be able to attach scope data to them, so we will wrap them in <span>
-      forEach($compileNodes, function(node, index) {
-        if (node.nodeType == NODE_TYPE_TEXT && node.nodeValue.match(/\S+/) /* non-empty */ ) {
-          $compileNodes[index] = jqLite(node).wrap('<span></span>').parent()[0];
+      for (var i = 0, len = $compileNodes.length; i < len; i++) {
+        var domNode = $compileNodes[i];
+
+        if (domNode.nodeType === NODE_TYPE_TEXT && domNode.nodeValue.match(NOT_EMPTY) /* non-empty */) {
+          jqLiteWrapNode(domNode, $compileNodes[i] = document.createElement('span'));
         }
-      });
+      }
+
       var compositeLinkFn =
               compileNodes($compileNodes, transcludeFn, $compileNodes,
                            maxPriority, ignoreDirective, previousCompileContext);