title: QtWebkit QWebView setUrl Memory Leak
body: <p>The virtual memory usage of my simple qtwebkit application increases forever.
  My qtwebkit app simply loops webView->setUrl(QUrl(QStringLiteral("about:blank")), as follows,</p>
  
  <pre><code>QWebView* webView = new QWebView(centralWidget);
  webView-&gt;setObjectName(QStringLiteral("webView"));
  webView-&gt;setGeometry(QRect(0, 0, width, height));
  
  while (true)
  {
      webView-&gt;setUrl(QUrl(QStringLiteral("about:blank")));
      msleep(1); // sleep 1 millisecond
  }
  </code></pre>
  
  <p>I think the memory usage should be stable in this case, however, the result is not.
  What's the matter? some kind of clearing is required to use setUrl() multiple times?</p>
  
  <ul>
  <li>Qt version : 5.4.1</li>
  <li>OS : Ubuntu 14.04 LTS</li>
  </ul>