Mixed content fix

service-worker/read-through-caching/index.html

@@ -82,8 +82,8 @@ limitations under the License.
       <div id="status"></div>
 
       <ul id="images" style="display: none">
-        <li><img src="http://www.chromium.org/_/rsrc/1302286216006/config/customLogo.gif"></li>
-        <li><img src="http://www.chromium.org/_/rsrc/1365117468642/chromium-projects/chrome-64.png"></li>
+        <li><img src="https://www.chromium.org/_/rsrc/1302286216006/config/customLogo.gif"></li>
+        <li><img src="https://www.chromium.org/_/rsrc/1365117468642/chromium-projects/chrome-64.png"></li>
       </ul>
     </div>