[css-images-3] Add EXIF auto-orientation to image().

Author: tabatkins

css-images-3/Overview.html

@@ -502,6 +502,9 @@ <h3 id=image-notation><span class=secno>3.2. </span> Image Fallbacks and
     or is a type that the browser doesn't recognize
 
    <li>use a solid color as an image
+
+   <li> automatically respect the image orientation specified in the image's
+    metadata
   </ul>
 
   <p>The ‘<code class=css>image()</code>’ notation is defined as:
@@ -520,6 +523,10 @@ <h3 id=image-notation><span class=secno>3.2. </span> Image Fallbacks and
    rel=biblioentry>[CSS3VAL]<!--{{!CSS3VAL}}--></a>) when a specified
    ‘<code class=css>image()</code>’ value is computed.
 
+  <p>If the image has an orientation specified in its metadata, such as EXIF,
+   the UA must rotate or flip the image to correctly orient it as the
+   metadata specifies.
+
   <h4 id=image-fragments><span class=secno>3.2.1. </span> Image Fragments</h4>
 
   <p>When a URL specified in ‘<code class=css>image()</code>’ represents

css-images-3/Overview.src.html

@@ -222,6 +222,9 @@ <h3 id="image-notation">
 		<li>specify fallback images in case the preferred image can't be decoded or is a type that the browser doesn't recognize</li>
 
 		<li>use a solid color as an image</li>
+
+		<li>
+			automatically respect the image orientation specified in the image's metadata
 	</ul>
 
 	<p>The ''image()'' notation is defined as:
@@ -231,6 +234,11 @@ <h3 id="image-notation">
 
 	<p>Each ''&lt;string>'' or ''&lt;url>'' inside ''image()'' represents an image, just as if the <a href="#url-notation">''url()'' notation</a> had been used.  As usual for URLs in CSS, relative URLs are resolved to an absolute URL (as described in Values &amp; Units [[!CSS3VAL]]) when a specified ''image()'' value is computed.</p>
 
+	<p>If the image has an orientation specified in its metadata,
+	such as EXIF,
+	the UA must rotate or flip the image to correctly orient it
+	as the metadata specifies.
+
 <h4 id="image-fragments">
 Image Fragments</h4>