CSP: Add 'self' as a vaid 'frame-ancestors' value.

Closes #461

Author: mikewest

specs/CSP2/index.src.html

@@ -2298,7 +2298,7 @@ <h3 id="directive-frame-ancestors"><code>frame-ancestors</code></h3>
     following ABNF grammar:
 
     <pre>
-      <dfn>ancestor-source-list</dfn> = [ <a>ancestor-source</a> *( 1*WSP <a>ancestor-source</a> ) ] / "'none'"
+      <dfn>ancestor-source-list</dfn> = [ <a>ancestor-source</a> *( 1*WSP <a>ancestor-source</a> ) ] / "'none'" / "'self'"
       <dfn>ancestor-source</dfn>      = <a>scheme-source</a> / <a>host-source</a>
 
       directive-name  = "frame-ancestors"
@@ -2334,7 +2334,7 @@ <h3 id="directive-frame-ancestors"><code>frame-ancestors</code></h3>
               <li>Abort loading the protected resource.</li>
 
               <li>Take one of the following actions:
-                
+
                 <ol>
                   <li>
                     Act as if it received an empty <a>HTTP 200 response</a>.

specs/content-security-policy/index.src.html

@@ -2404,7 +2404,7 @@ <h3 id="directive-frame-ancestors"><code>frame-ancestors</code></h3>
     following ABNF grammar:
 
     <pre>
-      <dfn>ancestor-source-list</dfn> = [ <a>ancestor-source</a> *( 1*<a>WSP</a> <a>ancestor-source</a> ) ] / "'none'"
+      <dfn>ancestor-source-list</dfn> = [ <a>ancestor-source</a> *( 1*<a>WSP</a> <a>ancestor-source</a> ) ] / "'none'" / "'self'"
       <dfn>ancestor-source</dfn>      = <a>scheme-source</a> / <a>host-source</a>
 
       directive-name  = "frame-ancestors"