Document.title getter should return text of title element and setter should stop when head el…

LayoutTests/svg/custom/multiple-title-elements.svg

 <?xml version="1.0" standalone="no"?>
 <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" 
   "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
 <svg width="400" height="300" viewBox="0 0 600 500"
      xmlns="http://www.w3.org/2000/svg" version="1.1" onload="test()">
 <script>
 
 var logOffset = 40;
 var logOffsetIncrement = 40
 function log(message)
@@ skipping 25 matching lines @@
 function test()
 {
     if (window.testRunner)
         testRunner.dumpAsText();
 
     expect('', document.title);
     document.documentElement.appendChild(createTitleElement('First title'));
     expect('First title', document.title);
     document.documentElement.appendChild(createTitleElement('Second title'));
     expect('First title', document.title);
+    document.documentElement.removeChild(document.getElementsByTagName('title')[0]);
+    expect('Second title', document.title);
 }
 </script>
 <g id="console">
 </g>
 </svg>