Update references to the extension messaging APIs to point to the "runtime"

chrome/common/extensions/docs/templates/articles/whats_new.html

Index: chrome/common/extensions/docs/templates/articles/whats_new.html
diff --git a/chrome/common/extensions/docs/templates/articles/whats_new.html b/chrome/common/extensions/docs/templates/articles/whats_new.html
index 4d92fbe40c5c9e8e26145372022735ca87e241e6..1588f741ac0c09c846f3b51b3042cb58f1c11720 100644
--- a/chrome/common/extensions/docs/templates/articles/whats_new.html
+++ b/chrome/common/extensions/docs/templates/articles/whats_new.html
@@ -115,7 +115,7 @@ made in recent releases.
     <li>The <code>sendRequest()</code> method
       has been deprecated in favor of the
       <code>sendMessage()</code> method for both the
-      $ref:extension.sendMessage and
+      $ref:runtime.sendMessage and
       $ref:tabs.sendMessage.</li>
     <li>The <a href="external_extensions.html">external_extensions.json file</a>
       has been deprecated in favor of individual