title: Appending chrome history to popup html and it keep flickering
body: <p>I am trying to append chrome history URL, lastVisitTime, and Sno, everything work fine when URL is print as static text.</p>
  
  <p>Problem arises when I print url's in table, it keep appending url, i don't understand this behaviour.</p>
  
  <p>Here is popup.js</p>
  
  <pre><code>var count = 0;
  var table = url = "";
  var tbody = document.getElementById('tbody');
  chrome.history.search({text: '', maxResults: 2}, function(data) {
      data.forEach(function(page) {
          count++;  
          url = page.url;     
          table += '&lt;tr class="table-warning"&gt;&lt;td scope="row"&gt;'+count+'&lt;/td&gt;&lt;td&gt;'+ url +'&lt;/td&gt;&lt;td&gt;'+page.lastVisitTime+'&lt;/td&gt;&lt;/tr&gt;'; 
          console.log('url', url);                    
      });
  
      tbody.innerHTML += table;
  });
  </code></pre>
  
  <p>popup.html</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
  &lt;head&gt;
      &lt;title&gt;History tracker&lt;/title&gt;
      &lt;link rel="stylesheet" href="bootstrap.min.css"&gt;
  &lt;/head&gt;
  &lt;body&gt;
   &lt;div class="container"&gt;        
      &lt;div class="row"&gt;
          &lt;div class="col-md-12"&gt;
              &lt;table class="table table-hover"&gt;
                  &lt;thead&gt;
                    &lt;tr&gt;
                      &lt;th scope="col"&gt;Sno&lt;/th&gt;
                      &lt;th scope="col"&gt;Website&lt;/th&gt;
                      &lt;th scope="col"&gt;Time&lt;/th&gt;                    
                    &lt;/tr&gt;
                  &lt;/thead&gt;
                  &lt;tbody id="tbody"&gt;                 
                  &lt;/tbody&gt;
                &lt;/table&gt;
          &lt;/div&gt;
      &lt;/div&gt;
   &lt;/div&gt; 
   &lt;script src="popup.js"&gt;&lt;/script&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>