Fix focus calls in Assistant oobe-dialogs

oobe-dialog have switched to cr-lazy implementation. Instantiation of
cr-lazy template and focusing button happens in same JS event, and
it seems to work incorrectly with a11y tree (at time of focus() the
button is not considered a part of the tree).

Fix that by postponing focus() call to the next render event.

Bug: 1024092
Change-Id: I435aa720c0eac176789ff82650a27ead2b7c45c2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2401458Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
Commit-Queue: Denis Kuznetsov [CET] <antrim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806183}

chrome/browser/resources/chromeos/assistant_optin/assistant_get_more.js

@@ -177,7 +177,8 @@ Polymer({
     if (!this.settingZippyLoaded_ || !this.consentStringLoaded_) {
       this.reloadPage();
     } else {
-      this.$['next-button'].focus();
+      Polymer.RenderStatus.afterNextRender(
+          this, () => this.$['next-button'].focus());
       this.browserProxy_.screenShown(GET_MORE_SCREEN_ID);
       this.screenShown_ = true;
     }

chrome/browser/resources/chromeos/assistant_optin/assistant_loading.js

@@ -155,5 +155,7 @@ Polymer({
    */
   onShow() {
     this.reloadPage();
+    Polymer.RenderStatus.afterNextRender(
+        this, () => this.$['loading-dialog'].focus());
   },
 });

chrome/browser/resources/chromeos/assistant_optin/assistant_third_party.js

@@ -234,7 +234,8 @@ Polymer({
     if (!this.settingZippyLoaded_ || !this.consentStringLoaded_) {
       this.reloadPage();
     } else {
-      this.$['next-button'].focus();
+      Polymer.RenderStatus.afterNextRender(
+          this, () => this.$['next-button'].focus());
       this.browserProxy_.screenShown(THIRD_PARTY_SCREEN_ID);
       this.screenShown_ = true;
     }

chrome/browser/resources/chromeos/assistant_optin/assistant_value_prop.js

@@ -354,6 +354,9 @@ Polymer({
         'click', this.hideOverlay.bind(this));
     this.valuePropView_ = this.$['value-prop-view'];
 
+    Polymer.RenderStatus.afterNextRender(
+        this, () => this.$['next-button'].focus());
+
     if (!this.initialized_) {
       this.valuePropView_.request.onErrorOccurred.addListener(
           this.onWebViewErrorOccurred.bind(this), requestFilter);

chrome/browser/resources/chromeos/assistant_optin/assistant_voice_match.js

@@ -183,7 +183,8 @@ Polymer({
     this.browserProxy_.screenShown(VOICE_MATCH_SCREEN_ID);
     this.$['voice-match-lottie'].setPlay(true);
     this.$['already-setup-lottie'].setPlay(true);
-    this.$['agree-button'].focus();
+    Polymer.RenderStatus.afterNextRender(
+        this, () => this.$['agree-button'].focus());
     if (loadTimeData.getBoolean('hotwordDspAvailable')) {
       this.$['no-dsp-message'].hidden = true;
     }