Doc change: Remove more proto scheme from src urls (to fix mixed content warnings).

Change-Id: I1c2276f5fb057a0ca20c0d1feef2bce0ab7ffab8
diff --git a/docs/html/tools/debugging/debugging-ui.jd b/docs/html/tools/debugging/debugging-ui.jd
index a5991ec..8ca5192 100644
--- a/docs/html/tools/debugging/debugging-ui.jd
+++ b/docs/html/tools/debugging/debugging-ui.jd
@@ -36,14 +36,14 @@
               <li>
 <iframe title="Hierarchyviewer" 
     width="210" height="160" 
-    src="http://www.youtube.com/embed/PAgE7saQUUY?rel=0&amp;hd=1" 
+    src="//www.youtube.com/embed/PAgE7saQUUY?rel=0&amp;hd=1" 
     frameborder="0" allowfullscreen>
 </iframe>
               </li>
               <li>
 <iframe title="Pixel Perfect" 
     width="210" height="160" 
-    src="http://www.youtube.com/embed/C45bMZGdN7Y?rel=0&amp;hd=1" 
+    src="//www.youtube.com/embed/C45bMZGdN7Y?rel=0&amp;hd=1" 
     frameborder="0" 
     allowfullscreen>
 </iframe>