<?xml version="1.0"?>

<overlay id="googleSearch"
         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
  <popup id="contentAreaContextMenu">
    <menuitem id="context-google-search" class="menuitem-iconic"
              label="Search Image on Google"
              image="chrome://google/content/logo_16x16.jpg"
              insertafter="context-viewimage" />
  </popup>
  <script type="text/javascript; version=1.7"><![CDATA[
    (function(){
    var GOOGLE_URL = "http://www.google.com";
    var browser = document.getElementById("content");
    var targetURL = null;
    window.addEventListener('load', function(){
      window.removeEventListener('load', arguments.callee, false);
      var menuContext = document.getElementById('contentAreaContextMenu');
      var menuGoogle = setMenu('context-google-search', search, 'S');
      menuContext.addEventListener('popupshowing', function(event){
        menuGoogle.setAttribute("hidden", true);
        if(gContextMenu.onImage ){
          targetURL = gContextMenu.mediaURL || gContextMenu.imageURL;
          menuGoogle.setAttribute("hidden", false);
        }
      }, false);

      function setMenu(id, callback, accessKey){
        var menu = document.getElementById(id);
        menu.addEventListener("command", callback, true);
        menu.setAttribute('accesskey', accessKey);
        return menu;
      }

      function search(e){
        if(!targetURL)
          return;
        var location = GOOGLE_URL + '/searchbyimage?image_url=' + encodeURIComponent(targetURL);
        browser.addTab(location);
        targetURL = '';
      }
      function searchFace(e){
        if(!targetURL)
          return;
        var location = GOOGLE_URL + '/searchbyimage?image_url=' + encodeURIComponent(targetURL);
        browser.addTab(location);
        targetURL = '';
      }

    }, false);

    })();
    ]]></script>

</overlay>

http://images.google.com/searchbyimage?image_url=http://www.google.com/images/srpr/logo3w.png

Yəni


http://images.google.com/searchbyimage?image_url=http://LINK/ŞƏKİL.png