Refactor feedback to use native JS object

components/dom_distiller/core/javascript/dom_distiller_viewer.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This variable will be changed by iOS scripts.
 var distiller_on_ios = false;
 
 function addToPage(html) {
   var div = document.createElement('div');
   div.innerHTML = html;
@@ skipping 134 matching lines @@
   // variable is set in distiller_viewer.cc before this function is run.
   if (distiller_on_ios) return;
 
   document.getElementById('feedbackYes').innerText = yesText;
   document.getElementById('feedbackNo').innerText = noText;
   document.getElementById('feedbackQuestion').innerText = questionText;
 
   document.getElementById('feedbackContainer').classList.remove("hidden");
 }
 
-/**
- * Send feedback about this distilled article.
- * @param good True if the feedback was positive, false if negative.
- */
-function sendFeedback(good) {
-  var img = document.createElement('img');
-  if (good) {
-    img.src = '/feedbackgood';
-  } else {
-    img.src = '/feedbackbad';
-  }
-  img.style.display = "none";
-  document.body.appendChild(img);
-}
-
 // Add a listener to the "View Original" link to report opt-outs.
 document.getElementById('closeReaderView').addEventListener('click',
     function(e) {
       var img = document.createElement('img');
       img.src = "/vieworiginal";
       img.style.display = "none";
       document.body.appendChild(img);
     }, true);
 
 document.getElementById('feedbackYes').addEventListener('click', function(e) {
-  sendFeedback(true);
+  if (distiller) {
+    distiller.sendFeedback(true);
+  }
   document.getElementById('feedbackContainer').className += " fadeOut";
 }, true);
 
 document.getElementById('feedbackNo').addEventListener('click', function(e) {
-  sendFeedback(false);
+  if (distiller) {
+    distiller.sendFeedback(false);
+  }
   document.getElementById('feedbackContainer').className += " fadeOut";
 }, true);
 
 document.getElementById('feedbackContainer').addEventListener('animationend',
     function(e) {
       var feedbackContainer = document.getElementById('feedbackContainer');
       feedbackContainer.classList.remove("fadeOut");
       feedbackContainer.className += " hidden";
       document.getElementById('contentWrap').style.paddingBottom = '120px';
       setTimeout(function() {
@@ skipping 205 matching lines @@
         shiftY: shiftY
       };
     }
   };
 }());
 
 window.addEventListener('touchstart', pincher.handleTouchStart, false);
 window.addEventListener('touchmove', pincher.handleTouchMove, false);
 window.addEventListener('touchend', pincher.handleTouchEnd, false);
 window.addEventListener('touchcancel', pincher.handleTouchCancel, false);