[css-device-adapt] Apply @Viewport to top level document only.

Author: Rune Lillesveen

css-device-adapt/Overview.html

@@ -387,8 +387,8 @@ <h2 id=the-atviewport-rule><span class=secno>4. </span>The <code
    rules. The declarations allow !important which will affect cascading of
    descriptors accordingly.
 
-  <p class=issue>Should the @viewport rule apply to top-level documents only?
-   If not, we need to say something about different zoom factors in frames.
+  <p><code class=css>@viewport</code> rules apply to top-level documents
+   only.
 
   <div class=example>
    <p>This example sets the viewport to at least 320px, but otherwise match

css-device-adapt/Overview.src.html

@@ -177,8 +177,7 @@ <h2>The <code class="css">@viewport</code> rule</h2>
       cascading of descriptors accordingly.
     </p>
 
-    <p class="issue">Should the @viewport rule apply to top-level documents only?
-      If not, we need to say something about different zoom factors in frames.</p>
+    <p><code class="css">@viewport</code> rules apply to top-level documents only.</p>
 
     <div class="example">
       <p>This example sets the viewport to at least 320px, but otherwise match