title: Accessing all the window variables of the current tab in chrome extension
body: <p>Can anyone post the code for accessing the window variables in chrome extension.
  I need to access the window variables when i click the chrome extension button.
  I am getting the window object, but not with all the variables loaded.
  I know we can create it by injecting the script. But i am not getting how to achieve it.
  Currently I am trying the following code to get the page source of the current active tab.</p>
  
  <pre><code> chrome.tabs.executeScript({code:
              "document.getElementsByTagName('html')[0].innerHTML"
          }, function(result) {
      var value = result[0];
      console.log(value);
      chrome.tabs.query({currentWindow: true, active: true}, function(tabs) {
          callback({
              url: tabs[0].url,
              title: tabs[0].title,
              jsonValue: value
          });
      });
  }); 
  </code></pre>
  
  <p>Please help me in solving this issue. It would be highly appreciated.</p>