Add migration to WebAssembly information to PNaCl / NaCl docs.

native_client_sdk/doc_generated/devguide/coding/nacl_io.html

Index: native_client_sdk/doc_generated/devguide/coding/nacl_io.html
diff --git a/native_client_sdk/doc_generated/devguide/coding/nacl_io.html b/native_client_sdk/doc_generated/devguide/coding/nacl_io.html
index 238cead04f8eb3590ac7060b51df71528820bfe2..ea6a8c23772fef6c2557f0da900c406a0e200b27 100644
--- a/native_client_sdk/doc_generated/devguide/coding/nacl_io.html
+++ b/native_client_sdk/doc_generated/devguide/coding/nacl_io.html
@@ -1,7 +1,15 @@
 {{+bindTo:partials.standard_nacl_article}}
 
-<section id="the-nacl-io-library">
-<span id="nacl-io"></span><h1 id="the-nacl-io-library"><span id="nacl-io"></span>The nacl_io Library</h1>
+<b><font color="#cc0000">
+NOTE:
+Deprecation of the technologies described here has been announced
+for platforms other than ChromeOS.<br/>
+Please visit our
+<a href="/native-client/migration">migration guide</a>
+for details.
+</font></b>
+<hr/><section id="the-nacl-io-library">
+<h1 id="the-nacl-io-library">The nacl_io Library</h1>
 <div class="contents local" id="contents" style="display: none">
 <ul class="small-gap">
 <li><a class="reference internal" href="#introduction" id="id1">Introduction</a></li>