Updating docs for appendText and insertingAdjacentText to reflect implementation.

tools/dom/templates/html/impl/impl_Element.darttemplate

Index: tools/dom/templates/html/impl/impl_Element.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_Element.darttemplate b/tools/dom/templates/html/impl/impl_Element.darttemplate
index cea6c0530a0b159c0dcac49b644d73f29efdf8c5..a6e165dc689e8a93b4890c3c08ec948df3e09b85 100644
--- a/tools/dom/templates/html/impl/impl_Element.darttemplate
+++ b/tools/dom/templates/html/impl/impl_Element.darttemplate
@@ -410,8 +410,7 @@ $(ANNOTATIONS)abstract class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
   Rect get offset => new Rect(offsetLeft, offsetTop, offsetWidth, offsetHeight);
 
   /**
-   * Adds the specified text as a text node after the last child of this
-   * element.
+   * Adds the specified text after the last child of this element.
    */
   void appendText(String text) {
     this.insertAdjacentText('beforeend', text);
@@ -550,7 +549,7 @@ $if DART2JS
     return 'transitionend';
   }
   /**
-   * Creates a text node and inserts it into the DOM at the specified location.
+   * Inserts text into the DOM at the specified location.
    *
    * To see the possible values for [where], read the doc for
    * [insertAdjacentHtml].