Make sure snap_page combined iframe serialized dom

telemetry/third_party/snap-it/popup.js

Index: telemetry/third_party/snap-it/popup.js
diff --git a/telemetry/third_party/snap-it/popup.js b/telemetry/third_party/snap-it/popup.js
index 17a92234ae74ca48479c9c83f36b85b7e40103e9..f3498d83fc54f192d5d4b4f74ac73f1ecf654e5c 100644
--- a/telemetry/third_party/snap-it/popup.js
+++ b/telemetry/third_party/snap-it/popup.js
@@ -33,7 +33,7 @@ function click() {
 /**
  * Takes all the responses from the injected content scripts and creates the
  * HTML file for download.
- * 
+ *
  * @param {Array<Object>} messages The response from all of the injected content
  *     scripts.
  */
@@ -52,7 +52,7 @@ function completeProcess(messages) {
 /**
  * Converts the responses from the injected content scripts into a string
  * representing the HTML.
- * 
+ *
  * @param {Array<Object>} messages The response from all of the injected content
  *     scripts.
  * @return {string} The resulting HTML.
@@ -102,7 +102,7 @@ function minimizeStyles(message) {
   document.body.appendChild(iframe);
   iframe.setAttribute(
       'style',
-      `height: ${message.windowHeight}px;` + 
+      `height: ${message.windowHeight}px;` +
       `width: ${message.windowWidth}px;`);
 
   var html = message.html.join('');
@@ -328,7 +328,7 @@ function unescapeHTML(html, nestingDepth) {
  *
  * @param {number} depth The nesting depth of the appropriate window in the
  *     frame tree.
- * @return {string} The correctly escaped string. 
+ * @return {string} The correctly escaped string.
  */
 function escapedQuote(depth) {
   if (depth == 0) {