[import] Adding "Style processign with Imports" section

This is a part of changes to address Bug 24616.

spec/imports/index.html

@@ -86,6 +86,7 @@ <h2 id="toc">Table of Contents</h2>
        <li><a href="#additions-to-script-enabling-criteria">Additions to Script Enabling Criteria</a>
        <li><a href="#additions-to-dom-document-currentscript">Additions to document.currentScript</a>
     </ol>
+    <li><a href="#style-imports">Style processing with Imports</a>
     <li><a href="#events-imports">Events in Imports</a>
     <ol>
       <li><a href="#additions-to-event-handlers">Additions to Event Handlers</a>
@@ -124,7 +125,10 @@ <h2 id="dependencies">Dependencies</h2>
 
 <h2 id="terminology">Terminology</h2>
 
-<p>HTML Imports, or just <dfn id="dfn-import">imports</dfn> from here on, are <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/syntax.html">HTML documents</a> that are <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/semantics.html#the-link-element">linked</a> as <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/links.html#external-resource-link">external resources</a> from another <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/syntax.html">HTML document</a>. The document that links to an <a href="#dfn-import">import</a> is called an <dfn id="dfn-import-parent">import parent</dfn> of the import. An <a href="#dfn-import-parent">import parent</a> which has its own <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/browsers.html#browsing-context">browsing context</a> is called a <dfn id="dfn-master-document">master document</dfn>. Each <a href="dfn-import">import</a> is associated to one <a href="">master document</a>: If the <a href="dfn-import-parent">parent</a> of the <a href="dfn-import">import</a> is a <a href="dfn-master-document">master document</a>, it is the <a href="dfn-master-document">master document</a> of the <a href="dfn-import">import</a>. Otherwise, the <a href="dfn-master-document">master document</a> of the <a href="#dfn-import-parent">import parent</a> is the <a href="dfn-master-document">master document</a> of the <a href="dfn-import">import</a>.</p>
+<p>HTML Imports, or just <dfn id="dfn-import">imports</dfn> from here on, are <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/syntax.html">HTML documents</a> that are <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/semantics.html#the-link-element">linked</a> as <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/links.html#external-resource-link">external resources</a> from another <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/syntax.html">HTML document</a>. The document that links to an <a href="#dfn-import">import</a> is called an <dfn id="dfn-import-parent">import parent</dfn> of the import. <dfn id="dfn-import-ancestor">import ancestor</dfn> of an <a href="#dfn-import">import</a> is the <a href="#dfn-import-parent">import parent</a> of the import or the <a href="#dfn-import-ancestor">import ancestor</a> of the import parent.
+
+
+<p>An <a href="#dfn-import-parent">import parent</a> which has its own <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/browsers.html#browsing-context">browsing context</a> is called a <dfn id="dfn-master-document">master document</dfn>. Each <a href="dfn-import">import</a> is associated to one <a href="">master document</a>: If the <a href="dfn-import-parent">parent</a> of the <a href="dfn-import">import</a> is a <a href="dfn-master-document">master document</a>, it is the <a href="dfn-master-document">master document</a> of the <a href="dfn-import">import</a>. Otherwise, the <a href="dfn-master-document">master document</a> of the <a href="#dfn-import-parent">import parent</a> is the <a href="dfn-master-document">master document</a> of the <a href="dfn-import">import</a>.</p>
 
 <p>The <a href="http://dom.spec.whatwg.org/#concept-document-url">URL</a> of an <a href="#dfn-import">import</a> is called the <dfn id="dfn-import-location">import location</dfn><!--, and the <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/origin-0.html#origin">origin</a> of the <a href="#dfn-import-location">import location</a> is called <dfn id="dfn-import-origin">import origin</dfn>-->.</p>
 
@@ -404,6 +408,13 @@ <h3 id="additions-to-dom-document-currentscript">Additions to document.currentSc
 If the Document is an <a href="#dfn-imported-document">imported document</a>, its <code>currentScript</code> is always null.
 </div>
 
+<h2 id="style-imports">Style processing with Imports</h2>
+
+<p>The contents of the <code><a href="http://www.whatwg.org/specs/web-apps/current-work/#the-style-element">style</a></code> elements and
+the external resources of the <code><a href="http://www.whatwg.org/specs/web-apps/current-work/#the-link-element">link</a></code> elements <strong>must</strong> be considered as input sources of the <a href="http://www.w3.org/TR/CSS21/intro.html#processing-model">style processing model</a> of the <a href="#dfn-master-document">master document</a>.</p>
+
+<p>Between declarations from different documents, the document order in terms of <a href="http://www.w3.org/TR/css3-cascade/#cascade-order">order of appearance</a> is defined based on the <code><a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/semantics.html#the-link-element">link</a></code> element of one of the <a href="#dfn-import-ancestor">import ancestors</a> that is in the same document of comparing declaration.</p>
+
 <h2 id="events-imports">Events in Imports</h2>
 
 <p>Events in <a href="#dfn-import">imports</a> is defined as a set of changes to the <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#events">HTML Events</a>.</p>