cros eula: Switch to loading screen before each load

Also removed obsolete 'eula-loading' class.

Fixed: 1068250
Change-Id: Ib7f1c08da113ba1af7934e12aee7434611f6e957
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2214528Reviewed-by: Renato Silva <rrsilva@google.com>
Commit-Queue: Roman Sorokin [CET] <rsorokin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#771564}

chrome/browser/resources/chromeos/login/oobe_eula.js

@@ -109,7 +109,8 @@ Polymer({
   },
 
   /**
-   * Event handler that is invoked when 'chrome://terms' is loaded.
+   * Event handler that is invoked when EULA is loaded. Either online version or
+   * 'chrome://terms' fallback.
    */
   onFrameLoad_() {
     this.acceptButtonDisabled = false;
@@ -124,6 +125,7 @@ Polymer({
     // This forces frame to reload.
     const onlineEulaUrl = loadTimeData.getString('eulaOnlineUrl');
 
+    this.eulaLoadingScreenShown = true;
     this.screen.loadEulaToWebview_(
         this.$.crosEulaFrame, onlineEulaUrl, false /* clear_anchors */);
 

chrome/browser/resources/chromeos/login/oobe_screen_eula.html

-<div class="step right hidden animated eula-loading" id="eula" role="group"
+<div class="step right hidden animated" id="eula" role="group"
      i18n-values="aria-label:eulaScreenAccessibleTitle" hidden>
   <oobe-eula-md id="oobe-eula-md"></oobe-eula-md>
 </div>

chrome/browser/resources/chromeos/login/oobe_screen_eula.js

@@ -227,19 +227,12 @@ login.createScreen('EulaScreen', 'eula', function() {
       chrome.send('EulaScreen.usageStatsEnabled', [value]);
     },
 
-    /**
-     * Event handler that is invoked when 'chrome://terms' is loaded.
-     */
-    onFrameLoad() {
-      $('eula').classList.remove('eula-loading');
-    },
-
     /**
      * Event handler that is invoked just before the screen is shown.
      * @param {object} data Screen init payload.
      */
     onBeforeShow() {
-      $('eula').classList.add('eula-loading');
+      $('oobe-eula-md').onBeforeShow();
       this.updateLocalizedContent();
     },